Share your entire iphone app list with others. I’d like an app that can do that. And share the folders you use to organize your apps. While, yes, many would argue they don’t want people to know ALL their apps. But then you could just “mark as private” specific apps.
It would be fun to have an automatically updated list of all the apps you own and whenever a friend downloads a new app, you get a notification. That way, when you see a new app a friend downloaded, you can ask, “Hey, how do you like that ABC app you downloaded?” And it would spur people to use more apps, and also creating more community with users of the iphone.
(btw, the image in this blog post features the super cool app, Star Wars: Battle for Hoth, available on the iTunes store.)