DrDoc - 4:14 am on May 3, 2009 (gmt 0)

Unfortunately, there is no such utility. In general, a site's accessibility and usability can only truly be measured after a manual review. The various tools/validators out there only serve to catch the most obvious mistakes.

How many different "types" of pages are there? It is certainly possible to have many pages, but only a limited set of page types. If that is the case, you could start by just validating each page type separately.