I always carry my C.S. X-2 Voyager, small Case, and small Schrade in my pockets. I would use my knives - or CCW pistol - as an absolute LAST RESORT - the legal nightmares would be terrible.
The only time I even came close to needing my knife for self-defense was when I stopped for gas in Kansas City. While I was filling my tank, a BIG guy started heading directly for me and didn't look very friendly. I gave him a hard look and pulled my X-2 about an inch out of my pocket. He saw me do it, and immediately changed his direction of travel. <img src="/ubbthreads/images/graemlins/cool.gif" alt="" />