Just want to let everyone know about a website called Drill the Kanji it is a web based Kanji review applet which runs on Java.
It can be used to review the Kanji for the JLPT not sure if it covers all levels as I haven't had much time to test it but 3 and 4 are covered. You can use the program to test your memory of both Kanji readings and English meanings. Haven't used it extensively but I think it is worth sharing.
http://www.asahi-net.or.jp/~ik2r-myr/kanji/