Our school blocks lots of stuff too. Almost all the proxies you can find easily are blocked, and if you do find a new one, they will block it in a few days.
So I somewhat cleverly came up with the idea to set up a proxy on my own computer to connect to over the internet. I have a dynamic IP address, so it will change every day or two, or each time I restart the modem, meaning they won't be able to block me because I'll get a new IP address every day
.
That's just the theory, as I'm taking 4.5 AP classes this year, one of which is a computers class, I don't really have much time to do other stuff on the internet anyways. I've not really looked very hard for something to set up a proxy on my computer, but a friend of mine did successfully set one up and connect to it at school, so I know it's possible.
Good luck,
Brijar!!!