If you ever let a helium balloon float away when you were a kid and wondered where it eventually ended up, you already know what Balloons for the iPhone is all about. This cute little app lets you launch a virtual balloon with a message and a photo attached. Anyone with the app installed call pull down balloons near them -- Balloons uses the iPhone's location services -- and read messages.

I grabbed a few balloons to see what it was all about, and it was more addictive than I expected. My first balloon was an ad, launched by some marketer near my city (Boo! Hiss!), but then things started getting interesting. I caught a balloon that had drifted from London to Texas to Arizona, picking up new notes along the way. Balloons reminds me of the message-in-a-bottle feeling of the early days of the Internet -- "Hey, who else is out there?"

I tested the Lite version of Balloons, which is free. There's also a $2.99 version that adds the ability to track your balloons, in case you get really serious. TUAW interviewed the developer at this year's WWDC.