eStorage for Revit Structure is the free ADN Plugin of the month:
http://labs.autodesk.com/utilities/ADN_plugins/
This add-in stores and manages the contents of external files in Revit extensible storage on selected elements in the BIM model. It is compatible with Revit Structure 2013 and 2012.
Scott Sheppard
Program Manager
Autodesk Labs
Autodesk, Inc.