I have finally figured out how to get the internal mic to work in Jaunty, although I think this fix will work for hardy, intrepid and jaunty.
You want to read this thread. Lots of useful info in there.
http://ubuntuforums.org/showthread.php?p=6589810I downloaded the script AlsaUpgrade-1.0.x-rev-1.16.tar, untar'd it then ran the command:
sudo ./AlsaUpgrade-1.0.x-rev-1.16.sh -di
This takes a while as it compiles a new version of ALSA for you. However this alone wasn't enough... I had to actually grab a recend snapshot of ALSA for the best support with this command:
sudo ./AlsaUpgrade-1.0.x-rev-1.16.sh -snap
Once this was done, I restarted and my Mic started to work in Skype, Sound Recorder and Audacity. Woohoo!
Finally full support for all my hardware, I couldn't be happier.