Okay, I've been discovering the joys of quizzes today. In a quiet patch at work I set my team a grammar quiz, with the grand prize of a bag of skittles going to the winner(!), and then I got home and found one for myself: http://www.realkana.com/ This is a great, and oddly addictive given its simplicity, little game that's helping my kana nicely. I particularly like the different fonts... Enjoy!