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.