I have created a simple tool to check basic accessibility of a web page using RAAKT (the Ruby Accessibility Analysis Kit). Trying it on Google Labs’ new accessible search interface yields interesting results.
If you want to help out with RAAKT testing, please have a look at the online web interface. With it you can test accessibility of remote web pages in a similar fashion to the W3C validator tool. As mentioned previously, one of the design goals is that RAAKT will only test machine measurable accessibility issues. In practice, this means that all web pages should pass all the time, there are no “if applicable” results.
If you find a bug, please report it at the RAAKT project page. For more information about RAAKT, see the previous entry Automated Accessibility Tests with RAAKT in Ruby on Rails.