Here’s a pretty neat Facebook demo. You login to Facebook and it loads your content into a WP7 embedded (in browser) emulator and you can see how your contacts would look when loaded. Here’s the link: http://apps.facebook.com/meetnewwpdemo/
Once you load it you’ll see your picture become the “Me” tile and then in People you’ll see your Facebook friends and even some of your pictures. There’s some generic items inserted so they can show you how it interacts and It’s really neat. Try it out for yourself.