I didn't really know which category to post this in, so here it is.
I found this article about User Interfaces, and since it mentions the FingerWorks products as well as other 'gesture' based hardware and software, I thought I'd point it out here. It's very much Mac-centered, but the basic concepts of Human-to-Machine interfaces apply no matter what platform you are using. Also, I should mention that a lot of the links lead to a YouTube video that demonstrate the tech.
Here's the address:
http://www.macobserver.com/columns/devi ... 5uis.shtml