This is a cute little pocket mental effect, based on--sort of--"Grey Elephants in Denmark." This effect is much more baffling than the well-known one, however, because of the apparent random selection of the first letter. You will need to make up the cards and supply a certain gimmick that you can either make cheaply or spend some money and buy commercially (see Mental Pen here on Penguin). (Forrest sells packets of the cards, which are colorful and highly recommended.) So you will ultimately need to spend a little more money than the half-sawbuck, depending on whether you want to do a homemade version or a slick, Cadillac version.

Either way, this is clever, though any mentalist who has used the gimmick will recognize what is going on. What I like about Forrest's thinking is that the seemingly random selection hides the method. While it's not a world-beater by any means, it's a cool, fun routine that is going in my wallet.