Download Firefox browser (
www.getfirefox.com) and download the extension SWITCHPROXY. (
http://mozmonkey.com/switchproxy/)
Now, go to switchproxy preference and load this URL
http://www.steganos.com/?area=updateproxylist.
This will load tons of proxies.
When you activate Switchproxy, your ip address will change every 4 - 8 seconds based on your preference.
NOTE: HOWEVER, sites that require you to store cookies can record your random IP in each cookie. And if your unique ID is discovered in another cookie during the same session they will still know your IP. Not exactly sure how it works 100%, but it's not bullet proof security. However a good program.