I downloaded the Opera browser (v. 5.12) just a couple days ago, after seeing a banner ad that announced it was now free--its former status as nagware had kept me from enjoying it in the past.

(Don't tell anyone I actually clicked a banner ad! I'll never live it down!)

The part of Opera that me as the coolest was the gestures. Just as though you were playing Black & White, waving your mouse a certain way (with the right mouse button held down) performs navigational tasks.

Me being easily amused, I have enjoyed--with actual fun--doing this for hours on end. It makes me feel like a wizard.

Here's how it works. (Remember, hold down RMB, or whatever your secondary mouse button is.)

Drag left - Go back.
Drag right - Go forward.
Drag down - Open new window (if you drag down from a link, the link opens in the new window).
Drag up - Stop.
Drag up then right - Maximize window (or restore it).
Drag down then left - Minimize window.
Drag down and right (or shake your mouse no) - Close window.
Drag up then down - Reload.