If you haven't already, check out Free Rice and test your vocabulary while donating rice to the United Nations World Food Program. I got a vocab level of 44- I knew those damn Wordly Wise books would pay off beyond the SATs! The highest level is 50 and I suspect I'll be addictively playing to try to get my score closer to that rarified level...
ETA: I hit 47 but can't seem to push through. damn- I'm going to have to start reading the dictionary at night to beat this website!
ETA2: I'm officially addicted. I'm stuck at 49, but can't seem to hit 50. I'll be feeding whole nations at this point just trying to hit the jackpot...
ETA3: I finally hit 50, on mangonel of all words. Who knew reading medieval romance novels would pay off in this manner?