This should really be made into a web service. Where all the new card decks are shared for free. I think it could become a very powerful collaborative environment.
FlashcardDB allows a choice between two spaced repetition algorithms: Supermemo's SM-2 (like Anki, Mnemosyne) or the Leitner System. New card decks are shared for free.
Thanks for the rec! The first thing I'm going to be using Mnemosyne for is scheduling guitar practice. I often forget the number of songs and scales that I actually know. Eventually, they get dusty enough that I won't remember them at all. I'm hoping this will help me to retain much better.
http://www.mnemosyne-proj.org/
it works on Win, Mac and Linux - written in Python