I'm not always all about the NXT, there are just several cool contests going right now, this one from LEGO:
NXT NXT...? Are you seeing double? Yes! We are presenting a doubly fun building challenge where you create a robot that uses 2 NXT bricks! We are also giving you double the amount of time to enter this challenge (projects must be entered by June 30, 2008).
The 2 NXT's can be onboard the robot or the 2 NXT's can be separate (for example if 1 NXT is used as a remote controller for the 2nd NXT). The NXT's must communicate with each other.
LEGO Mindstorms NXT NXT Building Challenge rules
http://blog.makezine.com/archive/2008/05/more_lego_nxt_contest_goo.html