If you’ve never tossed a bottle with a note in it into the ocean or, more in line with this app, sent a balloon into the sky with a note attached to it, you have to check out the Balloons app.  You can read more about it over at the official site, but the functionality is pretty straight forward.  Choose a colorful balloon from the app’s main screen, snap a picture with your iPhone and add some text if you’d like.  After you’re done, launch your balloon and track it to watch where it ends up.  As people catch your balloon, they can add their own text and pictures which you can track from the ‘Baloon Tracker’ screen.  I’ve launched a few myself and have had them caught all over the place, including one person from England!  It’s only $2.99 on the app store and is definitely a fun little app to play around with.