I think disabling third-party cookies (via your browsers preference) would accomplish this (though it's no VM), with the added benefit of not needing to re-log

I think disabling third-party cookies (via your browsers preference) would accomplish this (though it's no VM), with the added benefit of not needing to re-log in for each tab/window. This doesn't, however, block all tracking scripts, as some may get your IP via an embedded 1x1 gif or other request. There's still the issues of super-cookies, or Flash cookies, or scripts that embed a unique image in your cache and then read it out, etc. So for this I recommend AdBlock or Ghostery. Edit: Here's aseful link on this topic: http://samy.pl/evercookie/ http://samy.pl/evercookie/