I've been planning on making it for a long time, and for some mystery I've found myself with some spare time ... The result? A first Beta (or call it Alpha, if you will) of yet another free SEO analyzer. It'll crawl a pre-defined webpage, and tell you whether or not you've made good use of the meta-tags (description, keywords, revisit, ...), <H1/2/3>-tags, alt & title attributes with images, ...
At this point in time it'll only analyze your website title, the description & keywords metatags and some alt- and title-attributes from images.
I hope to keep developing it, so it'll properly parse hyperlinks (and see if you've made correct use of the rel="nofollow") tag, analyze emphasis of strong words on the page (using bold/strong-text), internal deeplinking within the page, ... There are a bunch of SEO tricks around, and given enough free time -- I'll implement them all :-)
Take a first glance, over at http://seo.mattiasgeniar.be/ and let me know what needs improving. It's got no layout whatsoever at this point, it's only a functionality check.