You could also consider using Macromedia Flash if possible.  It overcomes
many disability issues although it's not compatible with many "alternative
devices" (mentioned below) that can connect to and read web pages.  For
instance a flash site could easily speak the name of a button (or have other
sound cues) everytime the mouse passed over/near it and could read any
pertinent information on each area of the site.  It essentially becomes an
interactive movie.  You could even have areas of it cued to different kinds
of disabilities so that you could select settings based on the users's needs
and let them go it alone from there.  This kind of technology is in place at
http://www.connectability.ca/connectability/pages/sitetour/index.html, a
Community Living agency out of Toronto, Ontario helping people with an
intellectual disability.

You could consider Dragon Naturally Speaking to help with the physical
disabilities.  Although I've not tested it using Internet Explorer, I
believe it could be customized to access the internet without needing to
touch a keyboard.  Profiles are set up for the voice recognition of each
user and you teach it as you go.  This wouldn't work however with many of
the technologies mentioned below because this is a software solution.
(Although some devices are becoming more appropriately voice activated such
as some of the newer cell phones able to call mom by saying "mom".)

Another thing is that Web Designers don't usually make full use of tools
such as XHTML.  New language standards are emerging in web design that will
allow devices like Cell Phones or other tools to connect to and
read/interact with the internet.  (This is the kind of technology that might
some day be able to let you turn your lights on at home while on vacation in
Fiji by logging into a website.)  XHTML allows the designer to "flag"
certain areas so that for example a user could connect to a website using a
some kind of reading device that lets it know how to handle each area (so
the lights in the example above wouldn't need to worry about information
such as pictures or other text, just commands meant for the lights).  In
this case, the improvement for disabled users comes from the union of the
website developer's code and the products that connect to it which so far
isn't happening widescale.  What we're left with are devices such as cell
phones that try their best to interpret older websites but are really just
scratching the surface.  You can thank the flood of websites designed by
Microsoft Frontpage and Macromedia Dreamweaver that make things simple for
average joe designers, but limit applications such as this.

     Aaron Watson, Information Management Facilitator
     Community Living Chatham-Kent

P.S.  I'm not disabled but it's part of my job to research accessibilty
technologies.  It's part of the reason I've been scanning this group.  Sorry
if I've jumped the gun with my "tech-talk".