I have been enjoying myself in the last few weeks with building SEO tools, based on the different API’s for Yahoo, Google, MSN, Technorati and so forth. One of the things coming out of that box is a PageRank checker, it’s quite cool, because it can do an image which displays the PR of the page it’s displayed on, like the one in the sidebar here on the blog.
Yoast.com runs on the Genesis Framework
The Genesis Framework empowers you to quickly and easily build incredible websites with WordPress. Whether you're a novice or advanced developer, Genesis provides you with the secure and search-engine-optimized foundation that takes WordPress to places you never thought it could go.