I recall seeing the plans for a simple walking, balancing robot constructed out of TinkerToys, and while surfing around aimlessly I ran accross it again. I thought I'd go ahead and archive the paper which described it just for fun. It seems like the kind of toy you should just go ahead and build so you can show it off in your cubical. The Cornell Human Power Lab has some videos of this and related projects at their website. Enjoy.
A couple of days ago I was talking about small robotic flyers, I should have known that somebody at the Seattle Robotics Society would already have done something like this. Check out BXFlyer Four Rotor Helicopter for a description of a four rotor robotic flyer similar to the commercially available DragonFlyer.