Like you said, most filters are applied on url's with suspicious keywords...so here's a few that should do the trick.

http://www.tomyslist.com/
http://zagvoo.info/
http://777surfer.info/
http://betahouse.info/
http://www.brassway.info/
http://www.stage6.info/index.php?q=&hl=3ed
http://www.jadeway.info/

Those are just a few working proxies I have, and none of the url's should trigger anything for you. Just let me know if you need more.