Wiggio is an online toolkit that makes it easy to work in groups. You can basically make a Wiggio group for any type of group you're in (a team, study group, organization, business, project, social group, etc.) and Wiggio provides you with a cool set of tools to communicate and collaborate within the group.
Looks cool! But, I am not so sure that students would want their teachers sniffing around their so called study groups :)