W00t, another app I recently saw and liked the interface was the TweetDeck app on iPod touch again. Its different from the Facebok app on iPhone but again very nicely done. Essentially it allows to interface with Facebook or Twitter (hence TweetDeck).

If you want some screenshots of these to get an idea of the functionality and the UI design just let me know - I will take some screenshots from my wife's iPod touch. Again not to just blindly copy - but get ideas only.