http://www.multiproxy.org/anon_proxy.htm
http://www.proxybench.com/proxy/proxylist.asp
http://dmoz.org/Computers/Internet/Proxies/Free/
http://www.stayinvisible.com/index.pl/proxy_list
http://users.pandora.be/gimmegimme/anprox.html

Heh heh, there should be enough stuff on those pages to last you a while. I love Google

Later,
mjk

EDIT: On proxybench.com you'll have to go to page 9 since the first 2000 proxies are for members only. That should still be plenty though