M-SudoKu is a J2ME version of the popular SuDoKu puzzle game. From version 0.8.0 on, M-SuDoKu supports an unlimited number of grids!!!
To run it on a mobile phone (or PDA), make sure that it supports CLDC 1.0 and MIDP 1.0 (these were the first J2ME specifications to be released, so any device claiming "Java support" should be able to run this game).
At the time being the only limitation is the requirement for a color display: the game won't run on monochrome displays.
You can download the game (and its source code) from this page; instructions to play the game can be found here, and the GPL version 2 under which the game is distributed is available on this page.
http://phonphun.altervista.org/eng/download.php