Awesome article! - Integrating External Document Repositories with SharePoint Server 2007

Learn to design, implement, and deploy a complete solution for integrating an external document repository with Microsoft Office SharePoint Server 2007. External repositories can participate in workflows and use task lists and extensible metadata.

Written by some MCS guns and MVPS!

More details can be found here:

https://msdn.microsoft.com/en-us/library/dd440954.aspx