Yah, I've had a number of email threads with Aaron Rasmussen, the guy behind that system. Smart guy, now working on a startup call US Mechatronics
http://www.usmechatronics.com
I love that it was "just" a summer project and I love that he tested on his brother.
guns: http://www.youtube.com/watch?v=pMkV8E2re9U http://www.youtube.com/watch?v=hQf0Q0JEdtE