We bought 4 licences of Tedds to help us supplement our in-house calculation packages.  In addition, we bought 3 licenses of Bluebeam which help us easily mark-up PDF drawings and coordinate drawings in real time online with multiple users (it is Adobe Pro on steriods).   We are also considering buying SDS/2 Connect after our 30 day trial to help us coordinate 3d steel connection design within Revit.     These new programs, along with out current licenses of Etabs and Revit allow us to be at the state of the art in the engineering community.