Personally, I think that access keys are the wrong solution to the problem of accessibility. For normal non-interactive web documents, the issues of keyboard accessibility should be solved by the browser providing a better keyboard interface rather than the site providing its own additional keyboard interface.
I suspect that the original idea of access keys arose from the experience of computer applications providing a keyboard interface. The trouble with this thinking is that most Custom Web Design websites are not applications. They are just documents that can be viewed inside another application, the browser. In addition, the sites that are applications (like Gmail and other AJAX driven sites) will probably need more key definitions than that provided by those few miserable access keys.
When accessibility guidelines suggest access keys as a means to improve usability, you have many webmasters scurrying to implement them, hoping that they will make the browsing experience more pleasant for those with disabilities. But I think the reality is that the access keys add nothing to accessibility.
What do you think? Do you agree that access keys are irrelevant and useless for accessibility or do you think I've completely missed the point? Since this is just an opinion piece, rather than my usual tutorials, if you have any thoughts about it either way, feel free to drop me a note. For what it's worth, the access key to my feedback form is "9".