MIT's Open Courseware includes some video/audio lecture recordings. http://ocw.mit.edu/OcwWeb/web/courses/courses/index.htm#ElectricalEngineeringandComputerScience

http://techspeaking.denison.edu/Technically_Speaking/Home.html

You can get a Flip digital video camera for $150 (http://www.theflip.com/). It has been very helpful in our pedagogy course at UC Berkeley for first time TAs to use to tape and evaluate their teaching. It isn't professional quality video, but it is good enough to use for reflecting on teaching practice.

You can watch videos faster using plugins for Real Player and youtube. Students (in this day and age) can actually comprehend lectures at 1.5x - 2.5x speeds, depending on the professor. Suddenly an hour-long lecture can be made up in 25 focused minutes. [Enounce 2xAV offers a product called MySpeed which has a free trial and student pricing which works with Real Player and youtube.] I'm a student at UC Berkeley who re-watches lectures for midterm/final review (and for when I'm too sick to attend class). The software allows me to consume lectures twice as quickly and keeps me from getting bored. I've actually found that I learn most effectively with sped-up webcasts because they keep me engaged at a speed that I'm comfortable with. If I ever have trouble understanding anything, I can also slow down to .5x to make sure that I can get everything down on paper.