TeamSite - downloading content?

System

We are in the process of upgrading from TS 5.0.1 to 6.5. The content in the old system is such that it cannot in any efficent way be migrated to the new system. I have heard that content can be downloaded directly from our Internet site but cannot find documentation regarding the procedure. Is it really possible or was I given false information? If it is indeed possible, has anyone done this before?