I remember that I could do this by messing with input devices at the sound configuration menus, but it doesn't work anymore. I want to make the default input be a virtual mic that's the sound that's coming out of the speakers, while still being able to listen to it.
This solution allows you to record what you're hearing, but I don't know how to make it a default setting for anything. The instructions, updated for 11.10:
sudo apt-get install gnome-media pavucontrol
gnome-sound-recorder
and click on the record buttonpavucontrol
and open the Recording tab and pick the monitor interface of your outputIt seems that the gnome recorder defaults to that device afterwards, but I don't know if this persists across boots (or is indeed what you wanted).