[comicjk]

My way of learning a programming language is always to write a chess program in it (this is probably why I haven't learned any languages which don't encourage state). A multiplayer chess site would be a fun and challenging project.

[cgag]

I think you should check some of those languages out. Chess is used as an example in the Joy of Clojure, and I've seen it used to teach Haskell as well: http://www.youtube.com/watch?v=ScS8Q32lMxA (note, you can't really see anything here unless yout put it in HD and view in full screen).