Great little post by Gareth Spencer, showing that you can graphically filter unconnected nodes to allow for easier Structural Model validation:

Download PDF at:
http://www.cadlinecommunity.co.uk/Downloads/FileDownload.ashx?FileUrl=/WhitePapers/Autodesk_Revit/Revit_Structure/wp-cad-00194/docs/Cadline_Unconnected_Nodes_Revit.pdf

via
Using Filters To Highlight Unconnected Nodes – WhitePaper – CADline Community