First, understand that the restriction on MySpace may have been imposed due to security or productivity problems. The more you circumvent or bypass them, the more restrictions your school system will place.
Having that said, it may be necessary to bypass those blocks by going through another server known as a proxy. A proxy will be a middle-man between you and the Internet, and is often used to obfuscate your activity when accessing various Web sites, as well as provide performance improvements.
Here is a list of sites to try. They may not all work, but a google search should help you out. :-)
Now surf safely.
