Google Sightseeing is the first blog (that I know of) to do something I think will become ubiquitous: Provide a site KML file in addition to an RSS file, as a matter of course.

It makes most obvious sense for a site devoted to places as viewed via Google mapping technology, but all blogs that at least occasionaly post content involving locations should consider publishing KML feeds; they provide another way into the site — Google Earth users who subscribe to blogs’ KML feeds to surf geographically. A trivial example: One blogger might review one restaurant, another might review a competitor around the corner; GE makes the link explicit.