Social Media enable you to collaborate in many ways!

Wikis (Wikispaces)This space you are on right now is a wiki. A wiki is great for creating web content quickly especially if you want multiple people to edit it.

Collaborative Documents
(Google Docs) is one way to create documents that you can allow a few select users, to edit, keep private, or publish for the whole web world to see. To create a Google Doc you will first need a Gmail account.

Web Conferencing Tools
(Skype) is a powerful tool for having online group chats, voice calls, or even video calls. Many groups use Skype to conduct international conference calls for free.

Gaming + Crowdsourcing
Check out Betaville, an open-source multi-player environment created by the Polytechnic Institute of New York University in partnership with the University of Applied Sciences in Bremen, Germany, is a place where users can shape a virtual environment. Read more about Betaville. Google Sketchup is one of the 3D modeling tools used to create Betaville .