I have used the SVideo output of my laptop in the past (connected to a DVD recorder, but could also have used a DV camera with SVideo input if I had one) but the quality was a bit rubbish (low resolution, muddy colours, block artifacts from the DVD compression).
It should be possible to record directly to your hard disk, if not in real time (with older hardware it's really slow to get data back from the GPU to be able to save it to disk, with newer hardware you might get recordmydesktop or whatever exists for your OS to work sufficiently well) - you might have to record all the control changes during "show time" (with eg: [textfile]) then play them back into your patch with output recording turned on (with eg: [pix_write] to save frames to disk if you're using Gem), then combine all the frames to a video file.
I should update my Gem DVD tutorial to mention this technique, and include pd-generated sound, but time is lacking at the moment....
svn co https://code.goto10.org/svn/maximus/tutorials/gem-dvd/
related to this offline/non-realtime rendering technique: http://lists.puredata.info/pipermail/pd-list/2008-08/064343.html