I've looked through a few and by the life of me I can't find one that is doing something only available with 3.0. Google changed a lot of stuff with the UI, yet

I've looked through a few and by the life of me I can't find one that is doing something only available with 3.0. Google changed a lot of stuff with the UI, yet non of the apps seem to utilize windowing or other new stuff. This is really kind of annoying, since I'm trying to understand how all the new UI paradigms will work, and no example is to be found (at least not on my Xoom).