How long has google been offering things like "www" or "non-www" as default for all your site listings... thats quite nice. Also when did they include this tagging system for google images? I have seen a 120% increase in google images search referalls over the last 4 days since i opted in to it. Bringing 80+ uniques... thats very nice. If you havent used sitemaps in a while give it a try, it has really improved and offers alot more options than just upload a sitemap now.