Mac user? Here's a nice blog--and the "top 10 myths about the Mac and its accessibility to the blind"
Click on http://atmac.livejournal.com/7873.html to read information about VoiceOver and Mac OS X accessibility for blind and vision impaired people, especially comparing accessibility for OS X and Windows.
The blog itself, "ATMac: Assistive Technology for Mac Users," is a pretty nice read. I'm not a big Mac fan (no pun intended), but it's a great source of answers to some good questions from those of us who follow Jobs instead of Gates.