Cool New WP.com Feature

Just noticed Matt and co. have implemented the modified admin bar.  I had suggested Matt Read’s wp-admin tool bar plugin, and it seems a modified version is now in use.  Very cool.  Lorelle provided a link to a feed of wp.com sites, but I’d still like a list of all sites, or better yet, implement something similar to the new feature at technorati, in which your blog itself is “tagged” allowing you to find blogs by content.