VoiceThread - Conversations in the cloud
PBworks: Online Collaboration
PBworks in Education PBworks hosts over 300,000 educational workspaces, and has helped transform teaching and learning for millions of students, parents and teachers. Educators ranging from major universities like DePaul, school districts like Baltimore County Public Schools and individual teachers trust PBworks as their collaborative learning environment.
Getting Started with Google Docs in the Classroom - ProfHacker - The Chronicle of Higher Education
Excellent article on how to use Google Docs in the classroom. Also includes suggestions and pitfalls.
Welcome to Wikispaces - Wikis for Everyone
Create simple web pages that groups, friends, and families can edit together. Signing up and creating your own wiki space is fast, free, and easy.