LTris is a good Tetris clone with multiplayer capabilities (though i didn't test them). Works very good.

This time i did a more proper port and even packaged it in a deb (though no menu item at this time).



Everything is here (deb, source and changelog):
http://www.bundyo.org/maemo/ltris/

The original developer site is here:
http://lgames.sourceforge.net/