1. Play a game of poker without betting - maybe draw poker with a showdown after everyone has drawn the cards they need. The player with the worst hand (or maybe every player except the winner) must remove an item of clothing. This version is described in more detail on the Sunshine Nudist Club site.
2. Dave Sawyer has posted detailed instructions for a highly playable version of Strip Poker based on draw poker, and using an original two-chip mechanism to allow players to fold, but not too often.
3. Poker with betting. The levels of bet are various combinations of truth, dares and removal of clothing. Again, details can be found on the Sunshine Nudist Club site.
4. Play poker in which each player has a limited supply of chips. Anyone who runs out of chips has to remove an item of clothing to buy more. This version could be rather slow, but it is the basis of some of the Strip Poker software that has begun to appear.
5. Another version of Strip Poker is the basis of an American television show. It is played between two teams, two men against two women. The teams take turns to ask each other questions: if a team answers correctly they choose one of two cards to add to their hand; the other team gets the other card and removes an item of clothing. A more detailed description can be found at the Strip Poker Online site. From 2001 until late 2003, Finland's Subtv had a similar program called Räsypokka, hosted by Jaajo Linnonmaa. Unlike the US version of the game, the Finns allowed complete nudity on their show. I am told that hundreds of pictures from Räsypokka are available in the stripgameshows Yahoo! Group.

More about Strip Poker here: http://www.neverwinpoker.com/strip-poker