Not too long ago hiding your tracks on the Web usually meant finding an open proxy server to surf through or paying for proxy software like Anonymizer ($30), which redirects traffic through its own proxy servers.
Today there's a better solution, and it's free: the Torpark browser. Torpark is a Firefox-based browser designed to access the Tor network of encrypted proxies. When you use the Torpark browser, your Web session bounces through multiple secure proxies, encrypted all the way, until your request reaches its destination. Torpark is a quick download and doesn't require a formal install on your PC; just launch the executable when you need it and make sure the Tor Network icon is active when the browser starts.
Secure browsing is considerably slower than regular browsing, though, so skip it If you don't need the extra security---and most people don't most of the time.