We had an impresive Mindstorms stand with over 20 NXT models on display. Gerrit and I build a working Bowling ally that we demonstrated every hour. It was build with "Old school" technics, and 14 RCXs. we had over 40 Motors and many meters of wires. Building these masive models with NXT is still hard, due to cables and size of the motors.
Eric Build a masive remote controlled tank, and several nice NXT models.
Daniel created this audience shooter, that realy worked fast.
I presented the new Bulldozer and other technic models fitted with a NXT.
for more photos look here at my Brickshelf folder.