Wordle is a brilliant tool - I got students to write a bio poem then cut and paste it into Wordle, great success.
Twitter - use it to collaborate, investigate, a source of information. Get students to make observations and use Twitter as the tool. Keep classes updated with a twitter feed on your class page.
Google Docs - brilliant for collaboration on assignments, sharing documents, analysing exemplars the list goes on...
Storyonline - this is a brilliant primary/intermediate resource. Famous people from the Actors Guild reading their favourite story book - lesson plans included. Also great for all students to hear how to read a story.