You can also middle-click a bookmark folder to open each of the
bookmarks in that folder in its own tab.

Unfortunately, you can't middle-click a bookmark to open that
bookmark in a new tab. And you can't middle-click a tab to
close the tab, like you can in Mozilla (on Windows at least).

[If anyone's looking for a good multi-button mouse, I've seen
the
Wacom Graphire graphics tablet with wireless 3-button scroll
mouse and a copy of Photoshop Elements for less than $80. (But
it was a while ago.) I have the Graphire (I bought it before
seeing that bundle unfortunately) and it's pretty nice.]

Excellent tip!

I saw that deal in the Apple Store in Albany, NY a couple of
weekends ago and almost bought it, except when I checked with
the folks there they said that the mouse must be used on the tablet
to work, which I found a little too restrictive given the size of the
Graphire tablet. I instead bought a Kensington Pocket Mouse Pro
Optical, which I love--it has a compartment in which the USB
transmitter can be stored when you're on the move, tracks
beautifully, and works like a charm in Mac OS X with no need to
install software.

2¢--Books