MOG: A new competitor in the subscription-based music streaming arena, MOG sets itself apart by letting you download as many songs as you want directly to your iPhone or Android device for local playback. It also has a smart single-artist radio feature that lets you skip or repeat songs or see what's queued up. I wrote about the service at length, but basically if you're willing to plunk down $10 a month for a music subscription MOG is definitely worth investigating. Free, $10/mo.
Also available for Android

Tron: With the movie still six months out, Disney has released the o-fficial Tron app, which they'll be continually updating with premium content until the movie hits in December. For now, it's just a tanks-style game, but it's a damn good one, with some puzzle elements and plenty of neon thrown in for good measure. Free

Carcassonne: Adam Frucci, frequent visitor of the Carcassonne region, says:

The game is basically perfectly suited to make the transition from tabletop to touchscreen. It consists of a bunch of square tiles, each with features of a map on it. Elements include parts of roads, parts of cities and cloisters. You take turns placing the tiles down to create a finished map.
The actual competition comes in while you're making the map, as you're trying to complete various elements without letting your competitors complete theirs. So you're trying to build a big city or long road, while your opponents are trying to keep you from completing it or to hop on board to steal its points for themselves.
The iPhone version is a perfect translation of the game, one that improves upon the original with a solitary mode, very good computer opponents and the ability to see just what tiles are left and what moves are and aren't possible.
You can play either locally or online against friends or strangers, and a game can be banged out in about 10 minutes if you're playing against the computer or speedy opponents. It is incredibly fun.

I heeded his advice and bought the game, and it is indeed very fun. $5

Plunderland: A beautiful Pirate-themed side scroller with smart game play—tilt controls, conventional aiming, good physics—and a cool visual style. Overall a very fresh experience, and one that's tough not to like. And, c'mon, it's pirates! $3

acrossair: Acrossair, who's really having a go at making this whole augmented reality thing useful, just updated their app to support the iPhone 4's gyroscope. Turns out it makes AR browsing smoother than a tub of butter. Free.

Dragon Dictation 2.0: Brian Barrett, who probably SPOKE this instead of TYPED it, because he is lazy, says:

Dragon Dictation has been our favorite speech recognition app for a while, and today's 2.0 update only strengthens that opinion. Not only does it bring the requisite iOS4 compatibility, but you can now speak your tweets and Facebook status updates.

You can also send your dictated words directly to your text messaging client, if you're tired of fumbling around with that on-screen keyboard. Plus, speaking your tweets aloud in a public space might win you a bunch more followers. Or possibly get a slushie thrown in your face. Either way, you're making connections.

Say it with me: Free.

Skype: When Apple announced iOS 4's various flavors of multitasking back in April, two of the most compelling were background music (Pandora) and background VoiP (Skype). With Skype's new multitask-enabling update, we're two for two! Still no videochat, though. Free

Risk: Mark, who has never completed a Risk game without at least one ill-fated attempt to conquer Asia, says:

However, those playing on the iPhone and iPod touch will have access to some interesting multiplayer options. Up to 6 players can share one handset to multiplay their way through a game, or up to 4 can join one another over Wi-Fi or Bluetooth.
But the one, missing feature I'd like to see is online play. No, I don't want to connect to anyone in realtime over the internet, but a slower-paced, push-notification-based style of play could be perfect for killing time through the day-like Warfish, just on my phone.

That's kind of a bummer. How am I supposed to conquer the world with no internet multiplayer? $5.

Star Wars: Trench Run 2.0 Updating to Star Wars: Trench Run 2.0 gets you new levels—defend Princess Leia, protect the Y-Squadron during the Battle of Yavin—and new ships—Darth Vader's TIE, the Millennium F-in Falcoln—but best of all it lets you use your iPhone or iPod Touch as a controller for playing the game on your computer. Turning your iPhone into a starship that can make the Kessel Run in under 12 Parsecs? There's a paid update for that. $5 app, $1 upgrade

iBooks: iBooks has been updated with "substantial performance improvements when reading PDFs" as well as the ability to include in-book audio and video content. Because how will we make the next Great American Novel without the ability to embed YouTubes in it? Free.

Zen Bound 2: Casey! Unwind:

Zen Bound 2, previously exclusive to the iPad, is now available for the iPhone. It takes advantage of the iPhone 4's retina display and gyroscope to bring butter-like smoothness to the beautiful game.

Zen Bound 2 carries the same premise as the original Zen Bound: wrap up floating, rotating figurines with a rope. With the gyroscope involved everything feels slightly silkier and roping those damn totems now feels even more natural (not like I know what that really feels like). And the improved graphics are noticeable thanks to the Retina Display.

Only $3.