Tor

Well, now this is a great tool that I’ve been using for some time now, and never had any complain about it.
It’s basically a way to device anonymity in the internet, via a lot of routers.
Here’s a quote from their web site:

Tor is a software project that helps you defend against traffic analysis, a form of network surveillance that threatens personal freedom and privacy, confidential business activities and relationships, and state security. Tor protects you by encrypting your communications and bouncing them around a distributed network of relays run by volunteers all around the world. Tor works with many of your existing applications, including web browsers, instant messaging clients, remote login, and other applications based on the Internet’s TCP protocol.

Easy to install, easy to use, take a look at : http://www.torproject.org/