Can I use 3 displays with keynote

I would like to get another video card for a G5 and hook a 3rd display to it. I need to run keynote presentations while also monitoring an audio recording program. I would like to have a the main keynote presenter screen on one display and the viewing slides on the 2nd and have the 3rd shown me anything else I want. Is this possible or does Keynote lock you out of doing anything else when it's in presentation mode? Thanks