The editors of the American Heritage Dictionaries published the list of 100 words every high school graduate should know. You can find a list of the words here.

Matthew Baldwin, the writer of one of may favourite blogs defective yeti, wrote a small application you can use to test yourself a number of these words. Words Test.

Also, if you're a word lover you probably like scrabble. You might want to check out this Blitz scrabble.