Firefox 4 beta 12 (on OpenBSD) actually has a "Permanent Private Browsing mode" checkbox on the privacy tab. So you can already do this. ;-) That said, you may

Firefox 4 beta 12 (on OpenBSD) actually has a "Permanent Private Browsing mode" checkbox on the privacy tab. So you can already do this. ;-) That said, you may be interested in http://panopticlick.eff.org/ http://panopticlick.eff.org/, which shows just how private private browsing is...