It took a couple days, but I set up a web page for my version of autolevels, which is now revision 0.4
http://www.thebattles.net/video/autolevels.html
There are a number of ways this filter could be improved, but for now I need to set it aside so I can get back to my 8mm film conversion project. If you have any ideas, criticisms, or or questions, I'll be monitoring this thread, or you can email me at the address located on the web page I've just set up.
Edit 11/11/2010
I recommend not using this version, as the RGB path is too hacky, and the YUV path has only minor improvements over the 0.3 version. I'll release a better version soon.