A message from Joe Ellis, creator of the new and exiting free online kanji learning resource READ THE KANJI :

Read The Kanji is an ongoing kanji quiz project, focusing on reading kanji compounds from within the context of actual sentences.  Together with a stats tracking system, spaced repetition algorithm, and an easy to modify quiz platform, we are building Read The Kanji to be a fun way to benchmark your kanji reading ability. Currently we are putting together a database focused towards JLPT vocabulary, but we're hoping to add more varied words (proverbs, yojijukugo, etc.) as we go along.  Come give it a try and let us know what you think!