I agree... this is totally annoying. The Mac always thinks you're trying to zoom when you're actually trying to scroll.
If you're accidentally zooming in the Finder, you can disable this by going to Finder>Preferences>Advanced, and unchecking "Zoom using trackpad"
If you're accidentally zooming in other programs, there's a few options for you:
Jeff Hawkins of CubeYellow software has written 2 different InputManagers. One turns off 2-finger zooming in Safari and Firefox, and the other one turns off 2-finger zooming in Mail:
http://cubeyellow.blogspot.com/2009/01/mac-book-pro-trackpad-zooming-and.html
You could also use the program MultiClutch to assign a different command to zooming as well:
http://wcrawford.org/2008/02/28/everytime-i-think-about-you-i-touch-my-cell/
But most importantly of all, be sure to voice your concerns with Apple on their feedback pages at
http://www.apple.com/feedback so hopefully they will give us an option to turn this ABSOLUTELY HORRIBLE pinch to zoom option off.
Message was edited by: Scott Rose