In today's Email from Michael Quinion - he of the words site -
This commercial site, at http://www.dictionary.com/ allows you to look up a word from a variety of dictionary sources. A Q&A page allows queries to be posed to "Dr. Dictionary" (with an FAQ listing many answers). There are word games, online foreign dictionaries,and links to writing resources; you can also subscribe to a Word of the Day by e-mail.