Word Nerd
Some of you may have already run across this game, but I thought it was fun to play Etymologic. Here you can test your knowledge on the origin of words and phrases. For instance, did you know the term "checkmate" came from the Ancient Persian sentence, "esch schah mat", which translates to "the king is dead." I scored a 7 out of 10, but I inadvertently cheated.
Here's a brief HTML Primer