I've always wondered about Japanesepod101... I hear about it all the time but when I went there the organization of the site wasn't very good and the constant emails were annoying but then again I didn't pay for it.
Also I'd like to suggest;
The Kanji Game
It teaches the meanings of individual kanji. Honest to god dude, this is how I learned Grade 1-6 kanji
Despite its retro-ness and simplicity it's an awesome little game.
Annnd finally did you guys hear that smart.fm is shutting down? That was my favorite site for vocab D': iKnow is pretty awesome but it won't be free for much longer.