As announced some time ago, the latest Firefox 3.1 nightlies (Shiretoko) now feature a Private Browsing mode, where all user activity traces including history, cache, download history, saved passwords, searches, cookies, and others, are removed as soon as the user returns to normal browsing mode. To enter Private Browsing, select Private Browsing in the Tools

http://feedproxy.google.com/~r/MozillaLinks/~3/_MnMIQzABHk/