Making Ajax Work with Screen Readers

I recently came across this article about Ajax and screen readers. To quote:

The Web Accessibility Initiative's Protocols and Formats working group directly address the issue of making rich Internet applications accessible, and we borrow some of their concepts to investigate methods of ensuring that Ajax applications work with leading assistive technology products.

The article does more than just offer helpful hints. It also explains some of the inner workings of screen readers to help web developers understand why the techniques are required. A couple of Ajax form examples are also provided.