I came across a really eye-opening article in the February 2009 edition of Internet Retailer, (accessible online or as a reprint at Essential Accessibility) titled "Seeing the Light."
The article describes the available technologies to bring online retail sites up to par for disabled users of all kinds. Visually impaired users can use screen readers like JAWS, Window-Eyes, BrowseAloud and IBM's Easy Web Browsing. People with limited hand function can use "radar mouse" * that looks like a Doppler radar. When the sweeping line touches something a paralyzed person wants to view, he or she uses a finger or head-activated device to "click." It can also help customers check out by activating an on-screen keyboard.
Accessibility consultants like the SSB Bart Group, TecAccess, Virtual Vision Technologies and Thinkzo can assist with audits, training and JAWS (screen reader software for visually impaired) scripting to bring companies up to code with legal requirements including the Rehabilitation Act and the Americans with Disability Act (ADA).
Retailers can also do their own audits, following WC3 Accessibility guidelines or subscribing to SSB Bart's software-as-a-service Accessibility Management Platform ($1,000 per month).
For further reading on website accessibility (especially for web developers), check out the SSB Bart blog. Interesting topics include link text and image link accessibility tips, tips for the Adobe product Captivate and lightbox accessibility. (An example of a lightbox is a "Quick View" that pops up over a category page:
Making a retail site accessible can cost between $100,000 and $2 Million dollars (preventing a class action lawsuit such as the one filed against Target - priceless). But it can really make a difference to disabled consumers.
If you're curious how friendly your website is for disabled users, check out Deque's accessibility compliance tool.