So, you’ve got a gleaming new iPhone 3G. After you make a few calls to tell your friends, snap a few pictures, and try out the Web browser, it’s time to load that thing up with software. After all, this device lets you go way beyond the usual calling, texting, and surfing.

Apple’s communicator extraordinaire knows how it’s moving in space, can tell where it is on the planet, and lets you control it with multi-finger gestures. Few desktop computers give programmers as many possibilities, and developers have responded with hundreds of applications. The 21 apps we’ve collected here will transform your new device into far more than a phone.

Stanza and eReader can turn it into an e-book reader. Zagat to Go ’09 makes your phone a restaurant finder that knows where you are, while OneTap Movies does the same for your local talkies. Want more immediate entertainment? Try Ms. Pac-Man and you’ve got a handheld retro-gaming console.

For aural amusement, soothe your ears with Pandora, which provides tunes you’re bound to like based on previous choices you’ve made. But if you’d rather tune in to your own music collection, stream it from your computer with Simplify Media.

Prefer making your own music? Produce dulcet tones with Ocarina, which uses the microphone and speaker of the iPhone to turn the device into a soothing woodwind instrument.

The application’s “globe view” even lets you share your creations with the world. And for the countless times when you don’t want brilliant thoughts to slip away, there’s Speakeasy Voice Recorder, which does exactly what its name implies.

We’ve got sports fans covered here, too. The free Sportacular keeps you up to date on your team’s latest results, wherever you are. Caddy.me Lite put the iPhone GPS to clever use. It helps you sink that little white sphere into the cup by letting you know exactly how far you are from the hole.

World sports fans will love Real Soccer 2009, which simulates professional footie games and even uses real player’s names—now you can take Ronaldinho with you! Some of the software we include can give your work life a boost, too. Air Sharing lets you wirelessly transfer files to and from computer. And Text Guru is full-featured text editor that finally gives the iPhone cut-and-paste capability.

Microsoft’s Seadragon, though mostly a technology demo at the moment, brings the promise of a new way to navigate huge amounts of information in a small form factor. Currently, it does impressive things with large collections of images, but its designers expect to extend its capabilities to documents in the future.

We couldn’t leave out everyone’s favorite after-work Web activity: social networking. The free Facebook app not only lets you keep up with your friends’ updates but also chat and take pictures for instant uploading to your profile.

The upstart—and also free—Yahoo oneConnect social-networking tool will actually aggregate several social-network feeds into one interface. You can check on your Facebook, bebo, Flickr, and other accounts.

You can also chat with Yahoo Instant Messenger contacts using the app. For even more instant messaging, check out BeejiveIM, which hooks you up with multiple IM services. It will set you back $13, though—considerably more than most iPhone apps.

In any case, don’t treat your iPhone simply as a mere cell phone, iPod, and mobile Web browser. That’s a darned good start, but this device can do much more.

To read full reviews of these apps, click on the links in this article or in the short summaries below. And to find even more software and Web applications for phones, PDAs, laptops, and desktops—make sure to visit our Software Product Guide.

Air Sharing for iPhoneAir Sharing (for iPhone)

$6.99 direct

Air Sharing turns your iPhone into a networked drive that can wirelessly transfer files to and from your computers, while also letting you view a wide variety of file types on your phone. At $6.99, it’s not cheap as iPhone apps go, but well worth the outlay.

BeejiveIM for iPhoneBeejiveIM (for iPhone)

$15.99 direct

Even when this app is closed, it can connect to multiple IM clients and send message notifications to the iPhone Mail app. To switch chats, simply shake the phone! One drawback: It’s pricey compared with most iPhone apps, at $15.99.

Caddy.Me LiteCaddy.me Lite (for iPhone)

|$9.99 direct

Caddy.Me Lite, which gives golfing yardage estimates accurate to within about 10 yards, can save you strokes when you’re caddyless on an unfamiliar course.

CameraBag 1.4CameraBag 1.4 (for iPhone)

$2.99 direct

Whether you’re a nostalgia buff, a photography student, or just someone who wants to spruce up your iPhone photos, the easy-to-use CameraBag lets you remake your images to resemble various photographic styles ranging from vintage snapshots to techniques used by noted photographers.

eReader 1.3 (for iPhone) : BookshelfeReader 1.3 (for iPhone)

Free

eReader does a decent job of presenting books on your iPhone, and I like the dictionary option, but acquiring reading matter needs to be easier and the software should support more file formats. Its quick bookmarking and ability to switch to reverse text mode (white letters on a black background) will be a hit with some.

Facebook for the iPhoneFacebook (for iPhone)

Free

Facebook’s iPhone app delivers a streamlined version of the immensely popular social-networking service, including status updates and basic chat, mail, and photo functions. But it could stand to be a little more robust—for example, by making use of the iPhone 3G’s GPS features.

Ms. Pac-ManMs. Pac-Man (for iPhone)

$5.99 direct

If you have a hankering for some old-school gaming, this version of Ms. Pac-Man for the iPhone delivers most of the fun of the arcade original, with a few extra features that enhance the overall experience.

OcarinaOcarina (for iPhone)

$0.99 direct

The first application that turns the iPhone into a musical instrument offers a well-thought-out, fun pastime that’s sure to impress your cronies.

The app makes innovative, unique use of iPhone’s features, teaches music concepts, and sports an eager community of song-score contributors. Not only that, it lets you hear performances from ocarinists around the world.

OneTap Movies for iPhoneOneTap Movies (for iPhone)

Free

The OneTap Movies iPhone app can help you locate a nearby flick when you’re on the go. You can watch trailers of movies you’re considering, too.

Pandora (for iPhone)Pandora (for iPhone)

Free

Pandora’s version of its user-customizable Internet music service for the iPhone keeps its simple charms and clean interface while eschewing a few of its more advanced features. It’s free, and sports an attractive, uncluttered interface. On it, you can keep using the Web version’s thumbs-up, thumbs-down ratings on songs.

Photogene (for iPhone) : LandscapePhotogene (for iPhone)

$2.99 direct

The scope of Photogene’s editing tools—which includes many that other iPhone photo-editing apps lack—makes this a very appealing app.

Real Soccer 2009Real Soccer 2009 (for iPhone)

$7.99 direct

Soccer diehards who can get past some wonkiness with the controls should be impressed with the graphics and the depth of the game play that Real Soccer 2009 offers. In fact, the number of options may overwhelm more casual fans.

Seadragon Mobile : Splash ScreenSeadragon Mobile (for iPhone)

Free

Seadragon is certainly an impressive technology to see in action on the iPhone. It’s free, and lets you view huge images with astounding zoom possibilities without downloading a huge file all at once. As a plus, it offers a slick slideshow feature. However, we await more functionality and a functioning Photosynth viewer.

Simplify MediaSimplify Media (for iPhone)

Free

Simplify Media offers an excellent way to share or listen to music streamed to your iPhone from your computer. It won’t stream secure AAC files to the iPhone, but it will let you share streams with up to 30 friends and displays artist bios and song lyrics.

SpeakEasy Voice RecorderSpeakeasy Voice Recorder (for iPhone)

$1.99 direct

SpeakEasy Voice Recorder stands out among the many voice-recording iPhone apps, thanks to its simple interface and ability to download files to play in iTunes. It’s very easy to use, lets you download files to listen to using iTunes, and offers five recording-quality options. A few technical limitations keep it from being a perfect solution, however.

SportacularSportacular (for iPhone)

Free

Looking for an easy way to keep track of the latest sports scores or your fantasy lineup on your iPhone? The free Sportacular has most of the bases covered with frequently updated scoring, stats, and other game info for your favorite sports.

StanzaStanza (for iPhone)

Editors’ Choice Logo

Free

With support for a broad range of content, Stanza is the most versatile e-book application for the iPhone.

Star Wars: The Force UnleashedStar Wars: The Force Unleashed (for iPhone)

$7.99 direct

The Force Unleashed casts you as an aspiring apprentice to Darth Vader, who dispatches you to eliminate the remaining Jedi knights around the Empire.

You can play through Story mode, which moves you from chapter to chapter to face new combatants (and unlock additional Force powers), or you can choose Survival mode, where you encounter an increasing number of enemies while you try to achieve a high score.

TextGuru for iPhoneTextGuru (for iPhone)

$4.99 direct

A full-featured text-editing app, TextGuru finally adds cutting and pasting to the iPhone. Its implementation isn’t ideal, however, and the interface could stand a few additions to make this a standout program.

Yahoo! oneConnectYahoo oneConnect (for iPhone)

Free

With the free oneConnect, Yahoo attempts to offer the ultimate social-networking app for the iPhone. But the interface is confusing, and although you get Yahoo’s IM service, oneConnect suffers from limited features.

Zagat to Go ’09Zagat to Go ’09 (for iPhone)

$9.99

Zagat charges more than the excellent free Yelp iPhone app, but some will want access to its trusted reviews of upscale dining establishments. Find nearby restaurants, hotels, bars, stores, and hotels based on your iPhone’s location.