I've been working on a variety of very cool Proof of Concepts with ISVs lately. Most recently I was in the labs with an ISV doing some work on Collaboration and Mobility was part of the solution - we decided to build out a Silverlight 1.0 for Mobile solution...very very cool :-)
If you've not heard of Silverlight for Mobile before then check out the landing page here for more information.
There is a great MIX presentation by Giorgio Sardo of Microsoft Consulting Services Using Microsoft Silverlight for Creating Rich Mobile User Experiences.
I managed to track Giorgio down when I was in our Microsoft Reading offices last week and took the opportunity to get him on film for a couple of minutes positioning Silverlight for Mobile - Enjoy!