I read a recent Popular Science article where it says Trevor helped with the unicycle motorcycle. This article here is essentially what it said in the Popular Science article; so it seems Trevor is quite the go-to guy when it comes to these types of things.
http://www.motorcyclemojo.com/articles/the-uno/
* Not disagreeing, just supplementing
Some other efforts that come to mind help illustrate the territory. Honda made a horribly unscalable walking mechanism in the ASIMO. It will never be more than PR. The best work from CMU & MIT's Leg Lab got spun out into Boston Dynamics. You've probably seen their "big dog" video. http://www.bostondynamics.com/content/sec.php?section=BigDog
Boston Dynamics is part boutique research firm and part startup. They'll probably be the first to sell a walking robot.
Honda makes a clunker, and the hungry, small companies make something that will actually work.