Surf Securely
I thought that this Safari feature was really cool. Now I wonder if there are any plugins for Firefox that would give you this feature. Rather useful, especially if you are surfing on a friends machine (or even if you just don't want certain sites showing up on your own box!).
http://www.apple.com/macosx/features/safari/
Safari protects your personal information on shared or public Macs when surfing the Web. Go ahead and check your bank account and .Mac email at the library or shop for birthday presents on the family Mac. Using Safari's new Private Browsing feature, no information about where you visit on the Web, personal information you enter or pages you visit are saved or cached. It's as if you were never there.
Safari also uses strong 128-bit encryption when accessing secure sites such as your bank or an online store, so you can transmit account and payment information with confidence.