Thanks to a recommendation on TechRhet from Eric Crump, Dave Blakesley and I gave Shinkuro a try yesterday. Shinkuro is a file sharing/collaboration application that allows for creating various work groups. Members in a work group can share files from their hard drives with the rest of the group. It's a P2P application. The software contains a built in instant messaging system and other features to facilititate the collaboration process. From what I can tell, this is very similar to Groove except that Shinkuro has a free download of their beta.