PuzzGrid - I posted this at MetaFilter too but I know there are some puzzle-y people here who might enjoy it. It's a neat little game of grouping and forming associations.
→[More:]The rules are explained briefly when you start a game, but there were more detailed explanations
in the MeFi thread. Numbers
357 and
368 are pretty good ones to get started, from among the more recent ones. Let us know if you make a new one!