How do you record your lectures?
If my lecture is done via a presentation (not my preferred method, but necessary for some classes), I record the audio of my lectures along with a "video" of the slides I use. I use Camtasia to record everything, so the only other thing I need is a microphone. 

When I give lectures at the blackboard I don't record them. However, for those lectures I provide a fairly detailed set of course notes.