gtk-recordmydesktop is brilliant and easy to use. You just open it and press record. Click a button on the top panel to stop it. Simple! Then you have a video screencast of whatever you were demonstrating on your desktop.
Installation is a breeze on ubuntu with:
sudo apt-get install gtk-recordmydesktop
Unfortunately I had a problem recording sound. I changed the Advanced>Sound>Frequency setting to 48000 but it still didn’t work. It worked fine BTW on my Jaunty notebook without any changing from the default settings. The answer was interesting to say the least. Under device, it said DEFAULT in capitals. Give yourself points if you can guess in advance where this is going ;-). Anyway, if you put something like CA0106 in instead it would produce an error message “Recording is finished. recordMyDesktop has exited with status: 768. Description:Could not open/configure sound card.” DEFAULT didn’t produce this problem. It simple jumbled / garbled the sound so it all appeared in the first few seconds of the screencast.
Solution: set the device to default instead of DEFAULT ;-). I was able to test it both ways back and forth and that was (unbelievably) it. I hope this helps somebody.
P.S. I should also mention I had changed ; default-sample-rate = … to default-sample-rate = 48000 in /etc/pulse/daemon.conf and made sure I was using PulseAudio as the Sound capture under System>Preferences>Sound. It can be hard to tell excatly what is was, or what combination of things, resulted in success and I’m going to leave it well enough alone for now and get screencasting 😉