WordPress.com offers a large variety of themes, free and premium (paid). I recently found a good theme on WordPress website but the only options it gave me were to use it in wordpress.com blogs or create new ones. Of course, I self-host this blog and I’d like to be able to use it here.
I searched the name of the theme in admin panel but it doesn’t show up in the results. Then with a quick search on Google, I was able to find a svn repository for downloading all themes available to wordpress.com blogs. The link is http://themes.svn.wordpress.org/. To download these, you would need a SVN client, and on mac I recommend SmartSVN.