Holding down the key while using the mouse scroll wheel zooms you in and out.  It also zooms centered on the mouse location, allowing you to quickly zoom in on a specific area.

Does anybody else notice that the direction of the scroll wheel used for Zooming is the opposite from IE, Visio, etc?   ...sorry, just get's annoying when flipping between docs.

Just flip your mouse around.
It's the same in NWare as in FireFox.  Who uses IE any more?
I'll put in a feature request for a "reverse zoom scroll" option.

Good idea.  Thanks for listening!
Actually, it works pretty good when I flip my mouse around.  New topic: the left and right mouse buttons are switched - can we get an option for that too?  JK

What is this 'IE' you speak of?

Exactly.
Or, if you are truly asking, "Internet Explorer"