|Synaptic's Touch Gesture - Zoom|
I did happen to see that my Synaptic touchpad had an option for gestures.
Pinch Zoom makes Chrome pages zoom!
The answer is to disable it if you don't use gestures on your laptop. It's not really convenient, I don't know why you would, but blame Apple. They put it on their laptops first. Well, 1 finger scroll rocks! http://www.synaptics.com/solutions/technology/gestures/touchpad/linear-scrolling. But the way I type, my opposable thumbs get in the way.
Works on Firefox 4 and IE9 too.