You know, I just remembered a part from X-Men: Evolution where Rogue asks him "What's up with the stupid playing cards" and he says something along the lines of, "Well, chere, it's like having fifty-two explosives in your pocket".
Quite handy, considering his power. He also charges small throwing knives, I think...and of course, can charge anything he touches to explode.
Gosh, I love Gambit.