Web Accessibility Initiative (WAI) 
The Web Accessibility Initiative (WAI) of the World Wide Web Consortium (W3C). Vast quantities of information and resources for making the Web accessible to all.
http://www.w3.org/WAI/W3C - References on Web Accessibility 
WAI resources, projects and research, papers and articles on Web accessibility.
http://www.w3.org/WAI/References/
WorldEnable 
Internet accessibility initiative in support of the international goals of equalizing opportunities for, by, and with persons with disabilities.
http://www.worldenable.net/
Adaptations 
Offers consulting services for professionals and consumers seeking information about accessible environments for the aging population and people with disabilities.
http://www.adaptationsinc.com/
Quintam 
Developed a Palm-based ADA compliance checklist designed to help identify accessibility problems in existing facilities.
http://www.adachecklist.com
Section508.com 
Offers section 508 compliance testing to companies via sponsorship programs.
http://www.section508.com
Criterion 508 
Specializes in Section 508, web accessibility, legal consulting, accessibility testing, and web site redesign.
http://www.criterion508.com/
National Center for Accessible Media 
Research and development facility that works to make media accessible to disabled persons, minority-language users, and people with low literacy skills.
http://ncam.wgbh.org/
BBC Blogs: Access 2.0 
weblog covering accessibility of technology in the digiatl age.
http://www.bbc.co.uk/blogs/access20/
NDA AccessIT 
Technical accessibility guidelines, advice, and resources from the Irish National Disability Authority.
http://accessit.nda.ie/