Boston Dynamics Rock!!
I mean, they probably will end up building terminators by accident but these guys are awesome. They've built some of the best robots I've ever seen. Big Dog is incredibly impressive even if it is noisy!
Here's their YouTube channel... http://www.youtube.com/user/BostonDynamics
My little boy must've watched Big Dog Evolution a thousand times! (That's when he's not pretending to be Cheetah!). Ah, yes - check out Sand Flea too.
When you think of robots being kicked by a 7 foot marine you imagine them falling over. When a robot slips on ice you imagine it tacking a tumble... Just check out Big Dog!
Note - I do NOT work for Boston Dynamics - I just really appreciate their nous, determination & focus. Basically - it must be one hell of a lot of (hard) fun working there!
Incidentally - IEEE Spectrum have a iPad "Robots" application - my lad likes that a lot. We got it for free during national robotics week (USA national I guess).