I was looking on ebay and saw a four prop RC craft that looked pretty cool for hacking into a robot base. It was too expensive, though. It was > $360 on ebay and > $650 on their site. I'm sure a lot of it had to do with the RC part of it encoding and decoding. If one were to make a simiar rig like 4 props with a pic and 4 n-channel-mosfets, and a tiny camera, I wonder how hard that would be to make that aerial contest mentioned in the article. Sounds really cool. The craft was called the dragonfly. Here's the ebay item. and RCBlimps sells the Dragan Flyer. No I'm not associated with them. What grabbed me was the simplicity of the navigation. All you have to do is speed up one side and slow the other side down so that the upward propultion is the same only the direction changes. It's probably simpler than it looks. I wonder how hard it would be to work out tilt sensors and such and keep the weight down. I'll bet there's probably a cheaper model than the dragon flyer yet a similar model out there.