There are some trick to open blocked sites,..
As far as i know use Proxy... there are 2 methods of using Proxy, setting the proxy from browser (in example: Internet Explorer - Internet Options), 2nd.. use web that give service open URL with proxy (example: http://www.freeproxy.ca/)
How to prevent it?
For 2nd method.. do i must list one by one all proxy site?

I don't know other methods to open blocked sites... please tell me the others.

thanks a lot

oh i already solve for the 1st problem... redirect 80, 8080, 3128, etc to my proxy server (ex: 3128)

how to solve the 2nd problem and other possibility