Wurth Electronics Common Mode Choke and Ferrite Bead Spice Models

I recently attended a lunch and learn presentation from Wurth electronics and learned a few interesting things.  First, there is a freely available RF simulator called RFSim 99 that can simulate with S parameters.  I found a copy of this at RF Globalnet (search for it under downloads on this site).  I played with it a little, and found it to be limited in value, but possibly useful for demonstrating and exploring S-parameters for a signal integrity engineer.  Another interesting thing that I learned was that Wurth has made a library of spice models of their common mode chokes and ferrite beads available in the LTSpice simulator from Linear Technology.  The models are available in an encrypted library that is included with this simulator.  At first I thought this might be useful for signal integrity simulation, especially for common mode chokes, however the models are encrypted and cannot be simulated in other SI spice tools.  It at least gives confidence that these models exist and possibly could be obtained by calling the Wurth Electronics sales rep.  Common mode chokes are used very often on differential signal lines such as LVDS in digital systems to limit EMI, but it is difficult to assess their affect on signal integrity without good simulation models.