If you're not already familiar with file syncing service Dropbox, you should be. The easiest way to describe Dropbox is that it acts as a type of online storage that gives you access to your files wherever you go, no matter which computer you're on, what OS you're using, and where you are in the world. No need to use a DVD, USB drive, or e-mail to transfer important files. However, Dropbox is really much more than that: you can access and work on files even when you're offline, share folders with friends and coworkers, and most importantly (for this writeup, anyway), sync settings for numerous applications without having to fork over any cash.

Why is this good? If there are multiple computers in your life—like a work machine and a home machine, or a desktop and a laptop, or all of the above—you probably use many of the same programs. Some of those programs might have their own built-in syncing services to keep things like your bookmarks or passwords up-to-date, but many do not. That's where Dropbox comes in—the free account offers 2GB of space (up to 100GB for paying customers) for you to do whatever you please. And since we like telling you how we use things, here are a few of our favorite Dropbox uses.

Sync your 1Password database

1Password is a password manager and auto-form-filler for the Mac that has been a hit among the Ars staff and readers alike. It's much more secure than the built-in OS X Keychain and lets you store tons of data, including credit cards, frequent flyer miles, addresses, phone numbers—you name it, 1Password can store it. Then, with a simple keyboard command in most major browsers (command+ ), you can instantly log into any website or fill out any form without having to remember thousands of data snippets.

One problem some of us began running into when we started using 1Password, though, was the fact that it lets you create very complex passwords and store them without memorizing them. This means that when you're using another computer, you're a little bit screwed if you want to, say, log into your bank's website from your laptop when you created a 15-character hexadecimal password through 1Password at home. This is where Dropbox comes in—you can sync your 1Password database across multiple computers so that you always have access to it and can always save to it, no matter what computer you're using.

In order to do this, you must first have the latest version of 1Password installed on all your Macs (make sure you have the licenses to do this, of course!). Make sure you have Agile Keychain enabled (as opposed to "OS X Keychain Format") by going into the 1Password Preferences > Keychain tab—Agile Keychain has enabled by default for some time now, so you shouldn't have to do anything here if you're running the latest software. Then, change the location where your 1Password database is syncing from somewhere on your hard drive to your Dropbox folder by clicking the "More..." button underneath the location path.

Once you save it to a Dropbox path, you can navigate to it using the same method on your other computer and choose the 1Password file you have saved in Dropbox. Voila! You are now synced over Dropbox.

Sync MacJournal entries

MacJournal is a journaling/blog software package that has gained popularity thanks to its easy-to-use interface and relatively clean HTML output, something that is important to us here at Ars. I like to compose my articles in MacJournal and then copy the HTML over to paste into our CMS (unfortunately, our CMS still leaves something to be desired when it comes to hooking up third-party software to save directly into it). I use a desktop machine as my main computer when I write, but I also travel and move around the house/city a lot on my laptop. This is inconvenient when I have a half-finished article saved in MacJournal at home and need to pick up where I left off while I'm on the road.

Again, Dropbox comes to the rescue by allowing me to sync my article database and access it from both of my machines. Once again, you must make sure to have the software installed on the computers you plan to use. Navigate on your computer to your home folder > Library > Application Support > MacJournal, and make a copy of your "MacJournal Data" file on your Dropbox folder. Then on the computers you plan to sync, go into the MacJournal preferences > Advanced. In the drop-down where it says "Open documents," pull down to "Open other."

Here, you will be able to navigate to your Dropbox folder and select the file you want to use. Do this on both computers so you're working off the same file.

The one downside to this method is that you must make sure to quit MacJournal every time you're done using it from either machine. If you don't do this, your entries may not be properly synced when you switch to the other computer, though I've had some mixed luck with this. If you make sure to quit every time you walk away to switch machines, though, you should be golden.

Sync Yojimbo

Yojimbo is a popular "information organizer" for the Mac that lets you keep track of all manner of information, from serial numbers and bookmarks to images and notes—and everything in between. Once again, you might find yourself hooked on using Yojimbo to keep track of your life, only to realize that you need some of that information while you're away from the computer that you saved it on. Yojimbo has built-in syncing over MobileMe, but if you're not keen on giving Apple $99 every year, you can easily set up Yojimbo to sync over Dropbox for free.

A method posted to the Yojimbo Talk mailing list was suggested by some of our readers, but don't worry if you don't speak Terminal-ese. The basic gist is to quit the app, make a copy of your Yojimbo library for backup, and turn off MobileMe syncing within Yojimbo on all computers involved. Then, just like in our MacJournal example, go into your home folder > Library > Application Support and move the entire Yojimbo folder over to your Dropbox directory. Once you do that, make an alias of the Yojimbo folder, now located on Dropbox, and put it back into your Application Support folder (make sure to remove the "alias" part of the folder name).

Once you confirm that Yojimbo is working and able to read your library from Dropbox, quit the app and perform the same steps on your other computer to create an alias from the Dropbox folder of your Yojimbo library. Open up Yojimbo to make sure it's reading from the right place, and you're good to go.

Network share for the virtual office

We realize that this one is an odd fit for this article since it's about syncing all manner of files instead of just settings, but since this is one of the main ways we use Dropbox here at the Orbiting HQ, we wanted to share it. At most IT-related jobs, there's a network share or five that can be accessed by all employees who need to share files—Photoshop files, supporting materials, PowerPoint presentations, spreadsheets, etc. But as more and more people start working from home, the idea of the network share is sort of disappearing, along with its helpful functionality.

Not so with Dropbox! Since you can share whole folders with other people, you can designate a specific Dropbox folder to act as your network share for the virtual office. For example, when I'm in San Francisco or Cupertino covering an Apple event, I have a script that automatically saves the pictures from my camera into a shared Dropbox folder. Then, someone on the other side who has access to that folder gets Growl notifications when new photos are added, allowing that person to choose the right photos to drop into our liveblog. It's like having a whole team there without all the travel costs!

In order to do this, you must create a new directory in your Dropbox and then go to the website to share it with others. You can either create and share a folder all at once (click the "Share a folder" button), or you can share an existing folder.

From there, you can add collaborators by entering their e-mail addresses and a custom message if you prefer. If your collaborators are also using Dropbox, all they have to do is click the link in the invitation e-mail and your shared folder will show up in their Dropbox (if they're not using Dropbox, they are prompted to sign up for a free account). Even if you use the wrong e-mail and it goes to an account that your friend or coworker doesn't use with Dropbox, the site will let that person use an existing login to access your folder.

Turn your iPhone into an e-book reader

Sure, there are a handful of ways to read e-books on your iPhone, but not every one is ideal. The Kindle app only works for people who have Kindle/Amazon accounts, and the Kindle-compatible book selection at Amazon is limited. Sending e-mails to yourself with PDFs attached works, until you forget to send that e-mail. But if you sync your e-book (or really any) PDFs to a folder on Dropbox, you can use the free Dropbox app on the iPhone or iPod touch to access them anytime.

One way to do this automatically without requiring you to futz around with files is to set up a Hazel rule to automatically transfer all PDFs to a certain directory within Dropbox. Then, just pop open the app and navigate to that folder to read all the PDFs and e-books you want—no e-mailing or Kindling required.

What do you like to sync?

Do you have any unique uses for Dropbox that we haven't thought of? There are millions of things to sync across computers—bookmarks, AIM logs, fonts—and we want to know what you use it for most often.