MSDN now allows you to download their webcasts for offline viewing. There was a workaround for this a while back, but this is much easier - you can download it as a WMV file.
Now I can download the webcasts on the Enterprise Library that I am interested in, and view them whenever I want - on a plane, riding in a car, or wherever suits me. Nice!
UPDATE: On the Enterprise Library note, here's a site with all of the webcasts from the Patterns and Practices team. They're the guys who wrote EntLib.