An ETAG is a HTTP header that is sent-behind-the-scenes between a web browser and an web server. This value is intended to control how long a particular file is cached on the client side.
There is an interesting side effect to this technology; ETAGs are saved on a machine even if cookies are deleted. Some people / software have exploited this fact to make an ETAG "act" like a cookie.
This means that simply deleting cookies isn't enough. One has to delete the entire web cache as well. That is a painful process to go through every time I surf the net on my test machine.
What is the most reliable way to prevent tracking that occurs by ETAG headers?