Back in the days before Mac OS X Lion (not to mention Mountain Lion), I used a handy trackpad gesture when I found myself mired in a particularly lengthy web page that would let me jump back to the top. I just swiped upward on the trackpad with three fingers and I was right back at the top of the page.
When OS X Lion hit, one of the many features it introduced was Mission Control, which you accessed by swiping up with three fingers (or all four, if you tweaked a setting in System Preferences). Mission Control is great and all (particularly when used with keyboard shortcuts), but it took away a useful tool of mine.
Earlier today, when working on a post about Mission Control keyboard shortcuts, I accidentally discovered a keyboard shortcut that let me jump to the top of a Web page. You may already know about this, but it was new to me, so I thought it might be new to others. The keyboard shortcut to jump to the top of a Web page is -- drum roll, please -- Command and the up-arrow key. I found it works with Chrome, Firefox, and Safari, and I suspect it works with other browsers as well.
In related news, you'd be right if you said Command and the down arrow let you skip to the bottom of a Web.