I've met Kim Krause, the founder of Cre8asite Forums about a year ago. Ever since I have known her, she has been the SEO advocate for usability. In fact, recently she has written an article that was sent to the E-Marketing News mailing list named Do Not Drop Your Web Site Off the Search Engine Cliff, it might have been overlooked due to Mike's new article on the whole true fairness of Google's PageRank discussed in the entry below this one named Filthy Linking Rich - Popular Sites Get More Popular.
But that short article contains just a fraction of what you can find in Kim's first (not sure if it is her first) e-book named How to Quench Your Web Site Visitors' Thirst. This book contains a wealth of knowledge that can that be used as a checklist for any SEM/SEO/Web Designer quench their visitor’s thirst. Most of the SEMs I know are not usability experts, in fact, with this document, you do not need to be a usability guru. The information contained here can be used over and over again to help make your sites user friendly. Well worth the fifteen dollar investment.
Great work Kim.