Collaboration is very popular in business and education. Everyday it seems there are new ways for students to collaborate online. Google Docs is a great way for students and teachers to share documents and collaborate. A new way to collaborate online are walls. Wall programs allow you create an online space for students to post ideas. Think of it like sticky notes on a white board. Many sites exist that have this feature but two of the easiest to use are Wallwisher and PrimaryWall.
Wallwisher is intended for a more sophisticated audience and may be better suited for upper elementary and secondary classrooms. It has a more mature feel and is better suited for the more tech savvy teacher.
PrimaryWall is designed with teacher and classrooms in mind. The themes are more kid friendly and they even have lesson plans and ideas to use it.
I have yet to use either of these programs in the classroom. If you use either one, e-mail me and let me know what you did and how it went.