This free reference tool from Answers.com can look up quick answers in a range of authoritative sources, while you're working with any application.
  http://www.answers.com  [Site Details]

Online English dictionary, thesaurus and reference guide. Includes word games, online translator, and word of the day feature.
  http://dictionary.reference.com  [Site Details]

The biggest multilingual free-content encyclopedia on the Internet. Over two million articles and still growing.
  http://www.wikipedia.org  [Site Details]