online document collaboration tool

5 Ways to Collaborate on Documents Online in Real Time
http://mashable.com/2009/02/21/online-document-collaboration/

http://www.weboffice.com/
Work more easily with coworkers, clients, and vendors in a WebOffice. Share documents, coordinate calendars, hold web meetings, manage tasks, build web databases, follow discussions, make announcements and run your business on the web. You can control access to sensitive files while allowing guests to view public ones, take polls, and manage expense reports. Customize your WebOffice with your company logo to create a branded WebOffice.
Hosted Collaboration and Document Management
http://www.microsoft.com/hosting/en/us/catalogs/hosted-collaboration.aspx


Fully Managed Hosting Solutions Including Exchange, SharePoint, Project And CRM
http://www.microsoft.com/hosting/en/us/catalogs/hosted-collaboration-details.aspx?solutionid=88ef642b-c4f1-4014-a2d5-c0c4b74e3d1f