Basecamp is a web-based, collaborative project management tool that allows sharing of project data internally and externally.

"You can export your messages, comments, to-do lists, milestones, and time tracking data in XML format. Basecamp also offers an API that allows you to access your data from other tools that you use or create."

Basecamp is a hosted-tool much like gmail or google calendar. They do their own backups and security. Basecamp gives you a lot of permissions granularity for project access and updating.