A Go Variant popularized (invented?) by ChessWhiz. Same as go, but with the additional restriction that no moves are allowed that are adjacent to the opponent's last move, side-by-side or diagonally. So, basically a "forced tenuki".
http://files.gokgs.com/games/2004/9/4/ChessWhiz-Xopods.sgf is a sample game played with these rules. Try a few 9x9 games with someone and see how you like it!
Tenuki Go players on KGS:
(Sebastian:) What's the point of this rule? Is it just to be different (like some people who recommend playing with differently colored stones) or does it add a new dimension to your game experience?
(ChessWhiz:) It's an entirely different game, not really like go at all. Although the fuseki can be similar to a regular game, the fighting tactics are totally changed. Just try putting a single stone in atari and watch your opponent squirm, as he must tenuki!
Alex Weldon: Yes, but he can play a one-space jump from that stone in atari, and you can't capture, because you must also tenuki. And so on.
wms: Just tried it. It feels very strange. Many moves become like ko threats - the answer you want, you can't play right away, so you must find a bigger move elsewhere, then jump back. Interesting, but to answer Sebastian - I'd say, the point is for you to have a bit of fun playing with it, but that seems enough to me!