Brian,
Have you considered doing a variation of McDonald's Aces? It is a great vanishing card trick that no doubt you've seen. I think a simplified version would make a nice Scam School episode. The Criss Angel performance is here:
http://www.youtube.com/watch?v=rDkEXBsLyhM
I perform it with a slightly different spin so that the spectators can't inspect the discards for the missing aces. I immediately gather them up, leaving the three spectator piles with just one unrevealed card face down--presumably the ace. This way I can hide the double-faced cards. The reveal at the end shows them with no aces at all-- and me with all four.
Matt C