Google Docs

Google docs is a great website for collaborative projects.  Students can work on the same presentation (convertable), worksheet (excel convertable) or document (word convertable).  Create a document then click share.  Add emails of the students in the group.  This will send the members a link so they can access the document.  Students can work on the document at the same time and from any computer with internet access.

https://docs.google.com/