Much of what is new and different in iOS 5 is easily apparent — especially with a little guidance from Apple’s website. You can access the camera from the Lock Screen. A swipe of your finger brings down (up?) Notifications Center. At least some of your newspaper apps got shunted to Newsstand. And so it goes.

iOS 5 is a huge update with a boatload of big new features. But it’s also stocked with a bunch of smaller less obvious new features, some of which you might not know even exist unless you did some digging. To help you out, I’ve done the digging for you.

What follows are brief descriptions of every (almost every?) iOS 5-specific option contained in the Settings app. Yes, there are new smaller features outside of Settings. But there isn’t room in one article to cover everything new in iOS 5. The Settings app is ground zero for new features. So that’s where I decided to focus. While a few of the new options are only relevant to selected iOS devices (Siri is only on the iPhone 4S, as one obvious example), most of then work on all devices capable of running iOS 5.

Notifications

Notifications adds support for the new Notification Center feature.

From Notifications Settings, you can select for Center listings to be sorted By Time (most recent ones on top) or Manually (your determine your own sort order). To change the manual sort order, tap the Edit button and drag items to the location you want.

By selecting an individual app from the list here, you can turn Notifications Center on or off for that app (we previously covered removing the Stock ticker from Notifications Center). You can also customize how notifications for each app will display. For example, you can select between a banner or an alert box as well as if you want an app’s alerts to appear on the Lock Screen.

Location Services

This is where you modify whether or not a particular app is able to use your location data for determining where you are at any given moment.

New in iOS 5 is the System Services settings. From here, you can choose if you want the Location Services icon to appear in the Status Bar or not. You can also select whether or not to enable a variety of location-related services, such as displaying and updating traffic conditions in Maps.

Sounds

With iOS 5, you can add custom sounds to more items than ever before — such as to the sending of tweets from the system. If you’re not satisfied with the preinstalled sounds for a particular sound feature, you can tap Buy More Tones, which transports you to the Tones section of the iTiunes Store app.

Especially noteworthy, you can select among different vibration patterns (which “play” when an alert sounds if you’ve enable the Vibrate option). In addition to the five pre-installed patterns, you can create your own custom vibration. For example, I created one to match the old “Shave and a haircut…two bits” riff. [Update 10:50 AM PT: As noted in a reader comment, this feature is available only if you first enable Custom Vibrations in Accessibility, as described later in this article.]

iCloud

Everything about iCloud is new, as the feature does not exist in iOS 4. iCloud’s main settings allow you turn iCloud syncing on or off for individual apps — such as Mail, Contacts, and Calendars. You can also enable Photo Stream and Find my iPhone from here.

Especially noteworthy is the Storage & Backup section. If you enable iCloud Backup, your device’s data backs up to the new iCloud service. This disables backing up to your computer when syncing. If you later do want to back up to your computer, you have to change from “Back up to iCloud” to “Back up to this computer” in the Summary section for your device in iTunes. You can set it back to iCloud when you’re done.

If you navigate to Storage and Backup > Manage Storage and tap on the name of a backed-up device, you’ll get a list of every app that is being backed up. You can individually turn on or off backing up for each app. This can be useful if you’re running out of space on iCloud. You can choose to backup just what is most critical. However, be cautious here. If you disable some app iCloud backups, and don’t additionally back up to your computer, you won’t have a complete backup anywhere.

Even if you don’t enable backup for your entire device, you may still be backing up features such as Documents & Data (which transfers iWork data to iCloud). Tap on an app, such as Keynote, and you’ll see a list of every backed document. Swipe on a document to delete it. This will delete the document from “iCloud and all of your iOS devices.”

Mail, Contacts, Calendars

I only spotted two changes to this setting. First, there’s an iCloud option, which simply takes you to the iCloud section just noted. Second, you can select which calendar you want as the default for the new Reminders app.

Twitter

With iOS 5, you can provide your Twitter name and password once and have it available to all apps. Once you have attempted to post a tweet from an app (assuming the app offers such a feature), it will appear in the Allow list in the Twitter setting. You can now decide if you want to leave Twitter access on or off for each listed app.

There’s also an Update Contacts button that will add Twitter names, if known, to the people in your Contacts database.

Safari

The main new option in Safari settings is Private Browsing. With this enabled, websites that you visit will not be recorded in the History list or otherwise leave evidence of your visit.

If you want to eradicate evidence of a website visited prior to turning on Private Browsing, go to Advanced > Website Data. Locate the website URL you want to eradicate and swipe to delete.

Messages

iOS 5 introduces iMessage, a feature that allows you to send text messages for free to other iOS 5 users. It works within the same Messages app that you use for standard text messaging.

You can turn iMessage on or off from this setting. You can also enable a Receipts option that “allows others to be notified when you have read their messages.”

In the Messages app, how do you know if a message will be sent as a text message or an iMessage? The word “Text Message” or “iMessage” appears in gray in the text box.

When is iMessage used? If the person you wish to connect has an email address or a iPhone number in your Contacts database, iMessage is used. “iPhone number” is itself an option in the Contacts app. If you enter a iPhone number in this field (assuming it really is an iPhone number), you can send iMessages to that person even if you do not have an email address for them.

Photos

This setting includes a new option to turn Photo Stream on or off, duplicating what you can just as well do from the iCloud and Mail, Contacts, Calendars settings. Photo Stream is the feature that sends photos taken on one iOS device to all other devices (including iPhoto and Aperture on a Mac) that support this feature and have it turned on.

With Photo Stream, you’ll never again have to connect your iPhone to your Mac via USB to import photos!

Store

New in iOS 5, you can set whether or not you want newly purchased music, apps and/or books to automatically download to all your other devices, when you purchase something from one device.

If you aren’t concerned about using up your monthly data bandwidth, you can enable downloads over Cellular Data. Otherwise, it only works when you are connected to a Wi-Fi network.

From this setting, you can also set if you want apps that work within Newsstand to automatically download new content when you are on a Wi-Fi network. Personally, I haven’t noticed any difference between when this is on or off.

The remaining settings are subcategories of the General setting:

About

Hidden in the About settings for iOS 5 is some great news for troubleshooters. Scroll down to Diagnostics & Usage. Tap it and then tap Diagnostics & Usage Data. Here you will find crash report and other Console-like documents. These are what you decided whether or not to automatically send to Apple when you first setup iOS 5. You can change your mind here.

Tap on a document name to view its contents. The actual text will likely make little or no sense to non-developers, but it can occasionally offer a clue as to what is behind a hard-to-diagnose problem.

Software Update

If there is a new version of iOS 5 available, you can select to download it from here. This avoids the need to connect your iOS device to a Mac or PC in order to update. It’s all part of iOS 5’s push to be “PC Free.”

Usage

New in iOS 5, here you will find a detailed listing of every app installed on your iOS device and how much storage space they have gobbled up (also covered in another TMO article). If you are running low on space on your iOS device, this can help you decide what you can do without (apps are sorted by size). Tap a selected app and you’ll have access to a button to Delete App. In a few of cases (notably Music and Video), you can even select to delete individual items (e.g., songs) from within an app.

Lower down, there’s a button that takes you to the same iCloud Manage Storage options that I described previously for the iCloud setting.

Siri

Here’s another case where everything about the setting is new in iOS 5. Siri is currently only available on the iPhone 4S. If you’re lucky enough to be one of the four million (and growing) people who own one of these devices, you can turn Siri on or off from the General > Siri setting.

Especially when in a public space, you may prefer if Siri’s voice did not respond to your questions; visual feedback is sufficient. If so, you can set the Voice Feedback option to Handsfree Only.

By default, Siri is activated when you press and hold the Home button — as well as whenever you put your iPhone to your ear. The latter option is especially convenient for tasks such as voice dialing. Just put an awake iPhone to your ear and say “Call Naomi” and it happens — not even one button to press or screen item to tap. Trés cool. You can turns this off via the Raise to Speak option — although I can’t imagine why you would.

Network

For this setting, the news is about an option that has gone MIA in iOS 5. On the iPhone 4S, at least for AT&T phones, the option to disable 3G access is no longer there. It is still present on an iPhone 4 running iOS 5.

iTunes Wi-Fi Sync

This one gets a bit complicated. So follow along closely:

Connect your iOS 5 device to your Mac (via the USB-Dock cable) and go to the Options section of its Summary screen in iTunes. From here, you can check, “Sync this iPhone over Wi-Fi.” After enabling this, the iOS device will remain listed in the Devices section of iTunes, even after you disconnect the USB cable.

Now, if (1) your iOS device is on the same local Wi-Fi network as your Mac, and (2) iTunes is open on your Mac — Apple says your iOS device should automatically sync to your Mac immediately after connecting your iOS device to a power source. However, this hasn’t happened when I’ve tried it. [Update 9:40 AM PT: Following a tip from Dave Hamilton, I was finally able to get my iOS devices to automatically sync when connecting to a power source. In order to do so, I had to (a) disable “Prevent iPods, iPhones, and iPads from syncing automatically” in iTunes > Preferences > Devices and (b) enable “Open iTunes when this iPhone is connected” in the Summary screen in iTunes for each iOS device.]

Rather, to perform a Wi-Fi sync, I go to the iTunes Wi-Fi Sync section in Settings on my iOS device and tap the Sync Now button. Alternatively, you can click the Sync button in iTunes on your Mac. They will both do the same thing. Further, when doing this manually syncing, it is not required that your iOS device be connected to a power source.

If your iOS 5 device is connected to your Mac via USB, and iTunes is running, tapping the Sync Now button on your iOS device initiates a wired sync, exactly as if you had clicked the Sync button in iTunes. This works even if you have not enabled Wi-Fi syncing.

Wi-Fi syncing (if enabled) and wired syncing are not mutually exclusive. You can do whichever is most convenient at the moment.

Wi-Fi syncing is entirely separate from the option to back up to iCloud. If you have selected to backup to iCloud, Wi-Fi Sync will skip the backup step of a sync, just as it would when syncing from your Mac in iTunes.

Passcode Lock

If you have an iPhone 4S, Passcode Lock includes an option to turn Siri availability on or off from the Lock Screen. If you turn it off, you won’t be able to use Siri when the iPhone is locked, until you enter the passcode. This is a security measure, preventing the possibility that someone with temporary access to your iPhone could use Siri to perform a harmful action (such as sending a text message to your boss telling him you resign from your job) — even if they didn’t know your passcode.

Keyboard

The Keyboard setting in iOS 5 sports a new “Shortcuts” item (also covered in another TMO article). From here, you can set a short string of letters to represent a longer phrase. When typing the shortcut in any text app, it expands to the longer text. It doesn’t offer as many options as TextExpander, but it’s free and iOS Shortcuts should automatically work with all apps.

Accessibility

As its name implies, Accessibility options are designed primarily to assist people with a disability (such as vision- or hearing-impaired). However, a couple of new features here may be of interest to all users.

If you enable Custom Vibrations, you will be able to go beyond the single custom vibration option in Sounds. You will be able to enter a separate custom vibration for individuals in Contacts. Edit a contact to add a custom vibration to the relevant field.

With LED Flash for Alerts enabled, the light used for flash photography will flash briefly whenever an alert occurs.

Multitasking Gestures

Multitasking Gestures is an option unique to iPad 2’s. This allows you to use four or five finger gestures to perform tasks. Pinch to go to the Home Screen. Swipe left or right to rotate among apps. Swipe up to reveal the multitasking bar. These gestures eliminate about 90% of the reasons to use the physical Home button.

One more thing…AirPlay mirroring

There is one new iOS 5 feature that, although outside of Settings, I cannot pass up mentioning.

AirPlay was introduced in iOS 4. Among other things, it allows you to stream video content from an iOS device to an Apple TV 2 wirelessly. To access it, you needed to select the AirPlay option from within a supported app. This ability remains in iOS 5. However, with the iPhone 4S and iPad 2, you can wirelessly mirror the entire device display to an Apple TV 2. Everything displays on your large screen, even the iOS device’s Home screen. I’ve especially had fun using this option to play games, such as Real Racing, that don’t require that you look at the iOS display to manage the controls.

To enable AirPlay mirroring, bring up the multitasking bar (double-click the Home button). Next, swipe left-to-right to access the iPod controls. The AirPlay mirroring button will be to the right of the fast-forward button on the iPad. On the iPhone 4S, you have to swipe a second time; AirPlay will be on the right side of the screen. After tapping the AirPlay button, select Apple TV. You’ll now have the option to turn on mirroring.

Bottom Line

iOS 5 is the most spectacular iOS upgrade since the original iPhone was released in 2007. Add together the quantity and quality of its new features and the total exceeds every other prior update. Plus it’s free. There’s no downside here. If your iOS device can run this update, get it. Period.

[Minor corrections/updates added at 8:45 AM PT.]