Yes! We can bypass the proxy server using Google. Lots of colleges, schools, offices use proxy to block websites, the same situation is in my college too. I was trying out to bypass the proxy, did several experiments none of them worked, used lots of software's but of no use. Today I just opened Google translate page to translate a technical stuff page from German to English and I just tried to translate an English page to English.. :P .. The first site which came into my mind is Youtube.. when I tried to do so then, voila! Youtube was opened on my browser. Then tried opening other blocked sites like rapidshare, megaupload and everything worked fine. :)
This works because when you browse through it, then the IP address will be of Google and not you.
I don't know why people block websites, there are several websites and several codes to bypass the proxy!