Has anyone tried ironing their deck? What I did once with a document was to put it on the ironing board, put a very slightly damp towel on it (not even moist, mind you, barely damp) and ironed it. Worked like a charm. It didn't, of course, completely do away with the creases, but it was usable.
Although I have never done it with decks, it should theoretically work even better, since the cards aren't even creased.