Augmented reality Twitter isn't new to the App Store, but their official geolocation service is just a few weeks old. How? Hacks! Twitter 360 is the first augmented reality Twitter app to support the official API, and it looks fanastic.
Previously, the only way to grab location data from Twitter was to scrape through user profiles or to rely on some kind of third-party geodata service, with which Twitter users could upload their current locations as individual Tweets. It worked, sort of, but it was janky and awkward. Now that Twitter lets you embed your location in each tweet without taking up any characters, things are different.
Most new iPhone Twitter clients support the GPS tagging feature, so there's no shortage of location data to play with, and Twitter 360 is one of the first apps to really take advantage of it. You can basically watch your Twitter friends leave their little narcissist droppings all over town in real time, rendered on a map or through your iPhone's camera. It's fascinating, if, you know, you're into loose acquaintances' latitudes and longitudes. (This is an acceptable thing, in this here 2009.)