Simple but Fun
Here is a game that takes a real basic concept and runs with it, The only downside being having to wait for other users to play and the very simplistic nature of the game makes it a bit boring after a while, perhaps you could randomly place stones on the board to make the placement process a bit more challenging, or put a bit of a othello spin on it by making some of the moves remove players placements.
Love the online play with in a MMF made Flash app!