xvidcap is an open source tool that records a video of your actions on screen.
When I installed the Ubuntu package for xvidcap, it would just seg-fault and close when I tried to record. So, I installed from source.
Before I get into it, however, I should mention that xvidcap never really worked perfectly for me. It was quite buggy in my setup. I tried recordMyDesktop and gtk-recordMyDesktop instead and would recommend you try that unless you have a specific need for xvidcap.
Before you can compile xvidcap, you'll need to install three other Ubuntu packages.
Here is the command line to install those.
sudo apt-get install libglade2-dev libxmu-dev gettext
Download the latest version of xvidcap from http://sourceforge.net/projects/xvidcap. Then, do the following.
./configure make sudo make install
That's it, you should now be able to run xvidcap from the Applications, Sound and Video menu.