AR.Drone seems also quite hackable, there is even an open source controller client for Maemo&MeeGo:
Re:When The Drones Come Marching In
by presidentender on Saturday January 29, 2011 @05:38PM
(#2156641)
How's the durability?
I've definitely rammed it into a wall or some other barrier a couple dozen times and it's still ok. I'm sure I'll end up having to replace a blade at some point but I hear this is relatively straight forward.
If you, at all, are thinking about getting one go for it. You'll love it.