A game of speed, challenge, and intellect? Anyways, a good game with a Very High buzz factor.
Best played with a large number of people (for obvious reasons). One person is designated as the dealer. (This person should be changed every round because the dealer is at a distinct disadvantage. Some people play that the dealer does not play on his/her turn.) The dealer begins by placing cards, face up, in a stack, and calls out the number on each turn. When two cards of the same number come up in a row, the first person to bring his/her hand down onto the top of the pile gets the top card, and is then allowed to "give out" the number of the card in drinks to whomever he/she wishes. Rounds end when the dealer runs out of cards.
Some people try to add some more fun to the game by requiring that all players have the 'snap hand' behind their backs. Others call snap on two face cards of same suit in a row, or cards in either ascending or descending order.