This link is for a program that installs some programs for you without admin rights. It will not install a program that stores data in program files and other directories like that.
Proxy time! This is a proxy that works at most schools. If you're going to open it, right click on it and make sure you open it in an incognito window (Google Chrome) or inPrivate (Internet explorer) window. That way it will reduce the chance of the website being blocked. (Does not work at Cabra)
This is a link to Minecraft cracked which you can play on cracked server's and such (google: "minecraft cracked server") if mediafire is blocked submit a form with places that you can download from.