Your unbridled optimism even in the face of reality has inspired me to give this a shot, thank you! It seems to be based on Weka, so it should be good.
On a first run, I don't really see how to record images from the webcam, it just says "waiting for samples". I'll play around some more and hopefully figure it out, thanks again.
EDIT: Ah, there's a detailed walkthrough which seems to work well!
(It is not a Python application but a Java application, but still as fun!)