Notifying webmasters of penalties
Google are making it a bit easier to find out how they are indexing your site and any problems they are finding along the way.
Because I use Blogger's BlogSpot domain, I can only customise the template for the page - not add any extra files to the site. However the sitemap facility does support Atom 0.3 feeds, which my blog does have, so I've pointed it to that feed. It says it will take a few hours to update, but it will be interesting to see what it says about my blog once it is finished.