Synonym Finder

"Have you ever found yourself writing and continually using the same words over and over again, struggling to find a different way to say the same thing? Then Synonym Finder is for you. It is a free, quick and simple service to find synonym's. It also has antonyms and definitions for words, a daily word (great for learning new words) and a list of most viewed words (makes you feel better that you aren't the only one using those words)."

http://educationaltechnologyguy.blogspot.com/2011/03/synonym-finder-find-some-new-words-so.html

http://www.synonym-finder.com/