http://www.calvin.edu/~rpruim/scrabble/ospd3.txt

It should be the same as the paperback books of the same name. As a little joke, it really *isn't* the official Scrabble player's dictionary, since it doesn't have the naughty words:

http://home.teleport.com/~stevena/scrabble/expurg.html

There are various other incarnations of the list floating around (search for SOWPODS, e.g.).