I recently had the need to record a video of some computer activity from my computer. I did it using iShowU which is a great video capture application. I was able to quickly and easily record a video of the application and save it as a quicktime movie file in no time.
The application has some nice functionality for setting up recording areas, moving the recording area, etc. It has a decent range of quality and compression settings.
The best part of this application is its price! It is sold for only $20.00 US!