An interesting site called The Phrontistery which I ran across in my search of Scrabble dominance. My primary interest was in this page, which lists all the valid two- and three-letter Scrabble words, but I branched out and there is much else to interest. There is a collection of 400 of the rarest words on the internet and other obscure word lists. I haven’t looked at the whole site, but I’d say it deserves a look-see for those fond of English.