I recommend CamStudio (v2.0 not above!)
http://www.camstudio.org
use the CSCD codec to capture and then some other for distribution (divx, xvid, wmv, etc). Capture voice uncompressed and then use mp3 at 56kbps or so for distribution.
Also, DebugMode Wink. It allows you to create Flash screen captures of anything on the desktop.
http://www.debugmode.com/wink/