During the Firefox 3.5 beta, a few people stumbled upon a neat, unadvertised feature. By twisting their fingers on a Macbook's multitouch pad, they were able to roll through their loaded tabs. But Firefox 3.5 (official) deactivated the trick.
Luckily, as Crunchgear explains, the multitouch trick can be reactivated! You can read the very simple instructions over at their site, then realize that you can actually modify the settings to use gestures beyond the twist (like a three-finger swipe). But until we see incorporation of middle-finger-activated autotrolling, we're holding our excitement at bay. [Crunchgear]