WRITING TOOLS
Babelfish: The greatest international translator that I know of, for when you just have to know how to say "Yo, those are some good cheese fries" in Portugese ("O yo, aqueles é algumas fritadas boas do queijo," in case it's an emergency). Try translating something into a foreign tongue and then back into your own for further enlightenment.
Dictionary.com and Thesaurus.com: Truly two of the most useful resources on the Net.
Internet Anagram Server: Cast off the shackles of phonics and discover the REAL truth.
JP Schoemer Communications: You thinks you knows how to write good? Well, even the best of us can use a touch-up now and then.
Morse Code and Phonetic Alphabets: Includes a Morse Code translator in both Java and CGI.
Online Etymology Dictionary: Don't know about you, but the origin of words is one of my biggest fascinations.
The Online Slang Dictionary: Maintained by a UCA-Berkeley student and updated frequently with submissions from browsers like you.
Traduku: Esperanto translator, available in English, German and Portugese. Guaranteed to make you the life of the party.