My class is using google docs for all of their writing. We have a good system of back and forth revising/editing where I can give the kids feedback, allow them to make changes until the writing is ready to be published. We also set up a form yesterday to conduct some research before writing a newspaper article. The kids have voluntarily used presentations to present some of their learning in our units of inquiry. We are also making use of google sites, mostly for literature circles. Kids complete weekly reading responses before meeting in class for their discussions. If you haven't checked it out already, you should have a look at google apps for education (www.google.com/a/edu). They offer a range of google tools, free for schools, and ad free too.
Let me know if there is anything else you want to know. :-)