Wow, I didn't know that existed at all! And following the same logic led me to the realization that shift+backspace exists too!
(But coming from Firefox, I found out long ago that Command+Shift+T doesn't work to reopen a recently closed tab in Safari.
Dannii, I've uploaded http://www.club.cc.cmu.edu/~ajo/dissemi ... enshot.png
in case you want to see what Safari's scrollbar looks like these days. It's the dark gray (alpha-blended) blob on the right side of the screen. It fades in when you start scrolling, and fades out after about half a second of inactivity.
Idea for a non-IF game: Someone should make an HTML5/CSS side-scroller where the object is to prevent your scrollbar indicator from colliding with obstacles traveling from left to right across the screen. This would naturally be highly browser-dependent and probably screen-size-dependent too, since you'd have to know the size and position of the scrollbar relative to the stuff on the screen.