If you're looking for a different kind of puzzle game for your Palm then you might want to have a look at LightSquare.
The game is actually a combination of two classic board games: Lights Out, where every board piece works the same and the goal is to turn off all the lights; and Merlin, the Electronic Wizard, where the objective is to turn on all of the squares on the border of the gameboard to make a square.
Both game modes in LightSquare are easy to play - you just need to tap on a square to turn the light on or off (or, at least, turn the square black or white). Having said that, Lights Out and Merlin are both pretty difficult to master and require a lot of patience to perfect.
LightSquare is can be customized in a number of ways - you can choose to change the grid size, and toggle the moves display on and off. A 'Best scores' section keeps track of your performance on LightSquare.
It might not be graphically-rich or very innovative, but LightSquare makes for a challenging game of skill.