Some countries or ISPs have their access rules for their people to access the internet. Like China’s government that blocks Facebook in their country for whatever reasons. Then some websites are only accessible from certain countries, but mostly allowed from the US. But you need the information from that website, so to bypass all those filters or access rules, you can use a web proxy.
What is a web proxy? A web proxy (proxy server that focuses on WWW requests only) is a server (a computer system or an application program) that acts as an intermediary for requests from clients seeking resources from other servers. A client connects to the proxy server, requesting some service, such as a file, connection, web page, or other resource, available from a different server.
I have a web proxy server that hosts on Google App Engine and is developed using Python. This feature was inspired by Amit Agrawal from labnol.org and the Mirrorrr project.
Update: I moved this service to http://ivankrisproxyserver.appspot.com/. Thanks.