Scott Hanselman's ComputerZen.com

I've been looking into Accessiblity lately as well as the Microsoft Accessibility Inititive [6].  The American's with Disabilities act requires that Federal Websites be accessible to all [1].    The W3C has a number of pages on Web Accesiblity, under the WAI working group.  These guidelines [2] and [3] offer a lot of guidelines and techniques [4] on how to write HTML that is up to snuff and accesible to all.  These extra tags and techniques allow Screen Reading Software [5] that linearize HTML and provide additional context, like which labels go with which text boxes.  You can test your website for accessiblity with online tools like Bobby.[7] 

[1] http://www.section508.gov/

[2] http://www.w3.org/TR/1998/WD-WAI-PAGEAUTH-0203

[3] http://www.w3.org/TR/1999/WAI-WEBCONTENT-19990505

[4] http://www.w3.org/TR/WCAG10-HTML-TECHS

[5] http://www.freedomscientific.com

[6] http://www.microsoft.com/enable  

[7] http://bobby.watchfire.com/bobby/html/en

[8] http://www.w3.org/WAI/ER/IG/ert