Diagnostic Styling Reloaded from Jens Meiert provides a bookmarklet that uses CSS to highlight accessibility issues on a web page. It points out things like deprecated elements, layout tables, missing alt attributes, style attributes and more.
Peachpit Interview with Zoe M. Gillenwater talks about Zoe’s new book Flexible Web Design and all sorts of web design issues. (Work alert: the podcast plays automatically and there are no controls to pause or change the volume.)
Collecta is a real-time search tool. It’s in beta. It checks news sites, social media streams and “popular” blogs. Take a look and see if you find it useful.
Echo is another beta you may want to check out. Echo is embedded in your site and gives you all sorts of social media features and tracking abilities.