Zoho Writer is still in beta, but I'm impressed with what I see so far! It's got modules for word processing, database, presentation, chat, organization, conferencing, and notetaking. I've run into kids who have problems transporting work from home to school and back again. First of all, this is FREE! Secondly, it's got functionality that would help kids to work around the problem of having PCs at home and access to Macs at school.
This would also be great for project work. I don't know how easy it is to track editing and see who did what, but if a teacher can log in and see that, it would really make grading group-work easy. I plan on enrolling in a distance education program and understand that we'll do group work--this seems like the best way to maintain that kind of work as well. I can see lots of possibilities here!