Use a proxy like everybody does. You still can't hide originating IP otherwise nothing will ever find it's way back to you. It's in the packet headers. The only reason anybody could ever have for attempting to hide IP is illegal activity....
but can you trust your proxy is my question? (I'm liking the looks of this for that general purpose) http://tor.eff.org/
The only way to truly hide your IP is to use an open wireless network (not yours) or a cyber-cafe. Your hardware mac number will still be in the headers, that's how people who have had network intrusion can almost prove any illegal activity wasn't them. Proxy or not, on a cable network your IP relates to the physical wire and there is no way to mask it, as it is far out of your control. The proxy still has to know where you are, and any traffic through the proxy has to know where it is heading.
