Addi Lam from the School of Creative Media in Hong Kong designed a working, dare we say, third-party Revolution controller for what he calls a senior design project. The interface was showcased at this year's Asia Game Show. From the article: About the time Nintendo was showing off the Revolution's pretty packaging and dropping hints about the future of game controllers at E3 2005, Addi was showing his teachers a video game he'd designed with a controller you tilted and turned to control. He called it Pebbles.
Granted, Lam's controller is not intended for mass production, but the article gives great insight into driving game innovation through education. Nice work, Addi!