So, being in school, and known as the nerd, I often hear "Dude, get me onto Myspace!". Most of the time I just say no, but if I can install a proxy directly into my site and allow students to go around proxies simply by going to my site and typing a web site into a text box and clicking "Go!" I can't even imagine the amount of traffic I'd get.

So, my question is, how hard is this? Any codes some one can supply?

Take a look at this site: http://www.freeproxy.ru/en/free_proxy/cgi-proxy.htm , which lists hundred of those websites you described. Maybe you can use them or maybe it will help you to make your own one.