Videos of lectures

I am experimenting with making videos of some lectures, and will be doing this with my field theory course in Spring 2009. The idea is to archive these for future students to use at a time when the field theory course is not being offered. I have been planning on using SPARK, which will be password protected. But I am also experimenting with Screencast. Here is a sample, from my test run in my E&M class. It is from the unit on the Foundations of E&M, in particular on the action principle for fields. (Note added 1/27/09: I have removed the link to Screencast because this is now out of date. You will be able to access the Screencast version of the first few QFT classes in subsequent posts.)