One of my colleagues sent me a link the other day to Web Site Grader, and asked me to check it out. I popped on over to the site and entered a few URLs to sites that I work on. I was pleasantly surprised to see how in-depth and accurate the analysis provided appears to be.
The utility is an SEO analyzer that rates your site in comparison to all of the other sites that have been analyzed using the tool. It offers quite a few interesting options, including the ability to compare your site to specific competitors, the ability to grade your site on specific keywords, etc.