Over the weekend, Brightkite released version 2.0 of their native iPhone app [App Store, Free] which allows users to update and interact with Brightkite on their iPhone and iPod touch. The new app brings with it quite a few new features including a new friending model, new privacy options, post-by-post update forwarding, and tons of UI enhancements.
For those who don't know, Brightkite is a location-based social networking platform which integrates with other services such as Twitter and Facebook. It's a lot like Twitter, except that you can tag your posts with location info. A good example would be posting a photo at a concert. The photo shows up on the Brightkite stream for that area as well as for anybody who follows you. Very cool!