As far as AR (augmented reality) Twitter apps go, Twitter 360 [iTunes Link] looks like the best of the bunch... so far. In what will no doubt become the top term of 2010, this augmented reality app allows you to track your friends via geolocation of their tweets. If you're into that sort of thing (or have an iPhone 3GS, since AR apps use the compass to position their markers). If the thought of strangers tracking you while you tweet creeps you out (and frankly, it should), rest assured that tracking is opt-in in that you can turn off geotagging for your tweets.
As Fast Company points out, a neat feature is setting your "limit" or range of detection for tracking tweets. You can set this to World and see just how far away everyone is from wherever you happen to be standing. So yeah, pretty soon we'll all be tracking each other all over the place. What could go wrong?
Twitter 360 is currently $2.99US and is from Presselite, the folks who snuck in the first AR app without Apple's detection. Thanks for opening the floodgates! Check out the video of the app in action, below.