These sites provide support for the writing process, everything from spelling, and vocabulary to graphic organizers and brainstorming tools, and some voice input tools:

http://www.dictionary.com - look up any word to check spelling, definition or synonyms.

http://www.visualthesaurus.com - it's just that - a visual thesaurus.  Very cool!

http://writeexpress.com/online2.html - online rhyming dictionary.

http://gigglepoetry.com/ - learn about poetry including how to write poems, limericks and more.

http://www.scholastic.com/kids/homework/flashcards.htm - make your own flashcards to practice vocabulary and spelling.

http://www.graphicorganizers.com/ - printable graphic organizing/brainstorming tools and pages.

http://www.eduplace.com/graphicorganizer/ - more printable graphic organizers, charts, brainstorming tools, etc.

http://www.bubbl.us - online brainstorming/graphic organizing tool.

http://www.giffy.com - another free online brainstorming tool.

http://www.idictate.com - for 1 1/4 cents per word, dictate into any phone and have an email transcription sent back to you.