Have you guys ever heared about Onion Routing? That technique might actually help in this case. One of the networks using this technique is Tor. However, I think that masking your IP is not a very useful option to ensure your privacy and security. Knowing what you are doing already helps much more than using proxies, virus/spyware scanners and firewalls. As McTavish says, just make sure that your computer doesn't do anything funny. That's not true. That information doesn't come from the GET-header, it comes from Apache, which gets it's information from the operating system that reads the packets. If those packets come from an anonymous proxy, then the proxy's IP will be on it. Your browser doesn't have anything to do with it. Anonymous proxies can completely hide your IP. Okay, except for the cases some script determines the client's IP address client side (I wonder if that's even possible in normal JavaScript...) and sends it to the server.
