There was a thread up here about Helicopters.
Check out these to videos, the first is neat.
The second you HAVE to watch, I find it almost unbelievable.
Helicopter Aerobatics: BO-105 flying through a forest in Germany:
http://www.wservernews.com/YQHAII/061211-Helicopter
Did you know you could do this with a helicopter? Aerobatics part 2:
http://www.wservernews.com/YQHAII/061211-Helicopter2