If you're into accessibility, don't miss Isolani's new site. He provides accessibility tips. As a developer who works at yahoo, and having co-workers that use screen readers, he has learned stuff you just can't know from not using this regularly...

Some great tips I haven't seen anywhere else. He has an article on not skipping heading levels, why? It turns out that those <h1><h2>etc tags are used by screen readers as a cool way to navigate content. It's like a table of contents. So if the user asks for H1, then H2 headers, if there none, but there is an H3, then he might miss it. (it would be nice if the screen reader software let users go to the "next available" heading level, but it doesn't work that way...)

He also suggest a heading before each form element. Since logging in is key to personalization of a site, if you hide the form code somewhere in a huge page of content, it won't be easy to find. Putting a heading right before the form makes navigating your site blind, much easier.

Enjoy :)