In this post I am listing Circumventor proxies Published in septemeber as a single post . So if you want a new circumventor, just search and find the latest or just search the archives of puzzlehacker. Happy browsing.
Remember you can use http:// or https:// while browsing using these proxies. Https will be the better option in my opinion.
Try all these one by one,if none of these works, your network administrator is a tough guy, he maybe getting these from here or from other sites. So get the proxies at the earliest before your administrator visits here!