I know, it seems nuts but I swear sites that have images with keywords in an image (I don't mean alt text here) seem to do better. In fact, I don't see any top ranking webpages for any of my keywords that don't have an image with their #1 keyword as the first thing on the page. I even tried it on one of my sites. I added a very legible gif (with my keyword on it) to the very top left corner of my site. That was the only change I made that crawl (no new incoming links) and I jumped up quite a bit. If I were google I would read images because it would be pretty hard to cheat at it. I don't know, maybe I've gone googly.
-Susan