Amazon is a good example of a company web site that offers alternate contents to handle the special needs of people who use assistive technologies. For example, if you open the site's main page with Lynx (the textual browser), you will see an informative notice like this:
This notice notifies the user that an accessible version of the web site is available at www.amazon.com/access. On Lynx, you have just to type g followed by the address and then press Enter. You will see the following:
As you can see, this page is completely different from the former, though its contents are basically the same. Again, Amazon offers a really effective way of handling users with particular needs.