One of the entries to iLounge's Design the Next iPhone contest is this video by Umang Dokey that (even though it's sideways) shows off a pretty neat rotating UI when switching back and forth from landscape to portrait views. It's got a very cool overlay for on-screen menu options as well, which is something we'd like to see more of on the actual 3G iPhone. In our opinion it's probably better than the actual winners of iLounge's contest, which you can see here.