I second that - an edited and concise screencast is worth much more than an non-edited one. PeepCode are a very good example about how to do this right!
About ubuntu - maybe this could be helpful: ?
http://remi.org/2009/04/16/how-i-record-my-screencasts
I think I'll stick with screenr, it limits me to 5 minutes per video anyway!
I second that - an edited and concise screencast is worth much more than an non-edited one. PeepCode are a very good example about how to do this right!