Android's Navigation Drawer is one of the major features of an Android phone. The drawer gives the user access to things like notifications (someone just send you a text message), to system events (Wi-Fi has changed) to which apps are currently running (depending on what "skin" of Android is in use). The user can open the Nav Drawer by just swiping down from the Status Bar. The Nav bar also brings a unique animation to the device. The user can draw, hold, and flig the bar open or closed.
Wouldn't that kind of animation be cool to add to your own app? Many apps today are adding sliding menues (think Facebook, Steam, etc..). Although they don't completely have the "swipe and play with" feel to it, it would be really nice to have. However finding the details on the Sliding Drawer was a bit tougher than I thought. After some time, I did find exactly what I was looking for, so let me save you the trouble of looking for it. I found a great tutorial on the Sliding Drawer over on Android People (Android Sliding Drawer Tutorial).
Have fun playing with it! The author is also kind enough to give the full source for the example project. Its great for just pulling it open and using whatever you would like.