And speaking of fun puzzles, I went on another search for a chess game. I wanted one that runs on Linux, is freely copyable, and is easy enough for me to beat now, but hard enough to be a challenge should I get any better.
GNUChess and Crafty both fit the first two criteria, but both clean my clock with both hands tied, and neither have easy settings to let me weaken their play. No fun. (Technically, you can turn stuff off on Crafty, but I never figured out how to strengthen it gradually.)
Then I found an article on devalia.org talking about this very issue. Seems there's a chess game called Phalanx that, on its easiest setting, is more than weak enough for me to win, but at its hardest, is strong enough for me to play for years to come.
Now I just need to play.