What's the purpose for Google as a proxy? We often use office/school/university connections, usually those services are set to provide more safety, blocking the access to undesidered web sites (the "black list"). What you can do now is use Google translator service (language tools) as a proxy to bypass the restrictions set for our connection!
You just need to type the following URL:
(www.blockedsite.com stands for the URL you need to go to...)
What you'll get is the translation (english to english!) of the page you want to see... your connection is directed to a google.com page so this page won't be blocked (would be blocked only with google.com on the black list), no matter what's the content.