http://thefiringline.com/forums/show...threadid=63425
For situations where deadly force is legal, but if you can avoid drawing attention so much the better.
Problem with most CCW that aren't firearms is that they don't give one enough stand off range.
Knifes are probably the most practical concealable non gun weapon. But IMHO it is easier to learn useful blocks & defenses with an ASP or stick.