Wow... this is SO EASY and nobody mentions it...
There's an easy way to get past MOST if not ALL school blocks with the command prompt. (cmd.exe) Just type in:
ping myspace.com
(or whatever site you want) it will give you the IP address, and just type that into the address bar, and if it blocks it once you click a link, just do what I did and bring your own laptop with Tor on it.
This procedure is described in detail at:
Confederate Axis of Darkness