Surrogafier is an easy to install three tier web proxy written in PHP.
include the ability to remove cookies, the HTTP referer field, the HTTP user-agent field, scripts on the page, and objects, altering the user-agent string to whatever you please, and tunnelling your proxied traffic through a second proxy.
If there existed a freely public install of this script, two standard proxies could be used, one entered in the proxy settings of your browser, and one entered into the publicly installed web proxy, to create a connection being passed between three separate proxy servers before hitting the final destination.