Step 1: Don't be stupid
Step 2: Https
Step 3: IP address
Type in myspace.com, and it should tell you the IP address of Myspace. It turns out the address is:
TYPE this in to the address bar. DO NOT copy and paste.
Step 4: Tunneling
There is a list of tunneling sites you can use, there's about 100 of them on that list so chances are one of them won't be blocked. There are a lot more proxy sites out there, just use google to find them.
If the rare chance that the link above is blocked, here is a few tunneling sites you can try (or you can use the methods in steps 1-3 to get in):
Step 5: Proxying
Anyways, if the first four steps didn't work, chances are your school is very tech-happy and will notice right away when you use a proxy.