You can find a small java3D memory game here: http://www.yousry.de/Memory-Game.html
You can play it via java webstart. Source code (gpl3) and binaries are available at: http://code.google.com/p/memory-game/
Here is a gamplay image:
http://yousry.de/blog/wp-content/uploads/2008/08/gme_first-300x269.jpg
For Mac users: After a osx java update webstart was unusable for me.???