I've been working on implementing accessibility requirements for a public facing site on MOSS. Though keywords such as "SharePoint accessibility" provide a number of results on Live Search or any other engine, I had difficult time in searching the appropriate resources. Thought it would be worthwhile sharing the resources that I found and providing a context around them. Here are these resources:
We have couple of white papers and articles on this topic, however, search engines are yet to rank them better to come towards the top. Here are these:
http://office.microsoft.com/en-us/sharepointserver/CH100948721033.aspx
http://blogs.msdn.com/sharepoint/archive/2006/04/24/improvements-in-accessibility.aspx
http://technet.microsoft.com/en-us/library/cc668367.aspx
http://technet.microsoft.com/en-us/library/cc716527.aspx
http://www.21apps.com/sharepoint/sharepoint-accessibility-is-moss-2007-accessible/
http://msdn2.microsoft.com/en-us/library/aa479043.aspx
http://www.sharepointblogs.com/mossman/archive/2007/03/08/css-friendly-control-adapters-in-sharepoint-2007-a-walk-through.aspx
http://blogs.msdn.com/eigilm/archive/2008/10/07/web-part-zone-adapter.aspx
http://blog.thekid.me.uk/archive/2007/05/01/another-day-another-accessible-moss-website.aspx
http://aks.hisoftware.com
http://blogs.msdn.com/sharepoint/archive/2008/03/19/slidedeck-for-accessibility-kit-for-sharepoint-building-accessible-websites-on-moss-2007-session-at-spc2008-now-available.aspx
http://www.spworks.co.uk/arf/what.aspx
http://www.sharepointblogs.com/tmt/archive/2007/10/20/Accessible-Web-Content-Management-Solutions-based-on-Microsoft-Office-SharePoint-Server-2007.aspx
http://www.hisoftware.com/uaccess/Index.html
http://www.w3.org/WAI/