Transaccess is a great site that matches assistive technology according to individual need. It is also an excellent resource for businesses and those involved in education because it lists many of the services available to those with disabilities as well as the best ways to accomodate them.
EnableMart offers many solutions for the disabled and sorts them by category so that it is easy to locate the best assistive technology for the need.
The availability and amount of hardware available for any kind of disability you can imagine astounds me. if you need a type of accomadation, you can find it!