I've designed a prototype folding knife/saw, which you can see at:
http://docs.google.com/leaf?id=0B7pHGy6XaimFMDFlZGY3NDctOTcxYi00N2Y1LWE0ZWYtNjI2MjA4MWYzODIz&sort=name&layout=list&num=50
It's totally original, designed from scratch using my CAD skills. It's a 3mm thick stainless...