Swapnonil Mukherjee offers a good explanation as to Why you should right align form labels. He suggests by showing good examples that you eye must travel a smaller distance to navigate from form field to form field when the labels are right aligned.

The Scrutinizer is an interesting site. It allows you to analyze your site against validators, Accessibility, Alternate Access, site access and load times, Browser Compatibility etc etc.

From the site:"Rather than creating direct links to various validators and link analyzers, one link can be used to submit to all of them. It simplifies the task of figuring out which application needs what type of URL (Domains only/HTTP/No HTTP) and also saves time and space by freeing up the code from unneccessary URLs."

Since the Booby site went commercial there hasn't been an easy way to test a site. Now there is Cynthia Says, WebXACT, HiSoft, Site Valet and WebAIM Wave. all discussed here at JuicyStudio.

The JK Rowling Flash/ColdFusion website has been praised for it accessibility.

Here are some publicly available examples of accessible Flash.

Sandra Clark has started a great series of articles at the Fusion Authority.

Some points of note:

• For some reason, the XML prolog (<?xml version="1.0" encoding="UTF-8"?>) throws Internet Explorer 6 into quirks mode.
• Because the [xHTML] specification requires that a DOCTYPE be the first line of a page, I tend to place my DOCTYPE in Application.cfm (as the first line).
• In HTML, there are some attributes which have no value. For example, an input tag could have <option selected>. In xHTML, this must be set at <option selected="selected">. Just make sure the attribute name and the value are the same.
  

The Colour Contrast Check is a very simple web-based tool that allows you to specify a foreground and a background colour and determine if they provide enough of a contrast when viewed by someone having color deficits. A great tool to add to your accessibility toolbox.

When we think of building accessible websites, we tend to focus on the visible disabilities. Juicy Studio has a phenomenal article on Developing sites for users with Cognitive disabilities and learning difficulties.

Some examples of good practice in utilising tables.

http://www.456bereastreet.com/archive/200410/bring_on_the_tables/