Instagram 3.0, the free photo sharing app for iPhone, is available and provides a number of enhancements. The most impressive is the new Photo Maps feature.
By grabbing geolocation information that is saved with each photo, Instagram creates a world map of your images by location. As you zoom in on each location, say Florida for example, you see locations in that state, then in each city.
You can add new photos to your Photo Maps through the new photo upload screen, which features a prominent Add to your Photo Maps button. Instagram has also increased the length of the captions you can add to each photo, and provides a way to name a location.