So I just made my blog georss compatible.  Kinda geeky, but for every post, it will have a location signature to it, specifically, latitude and longitude.  So if i write about a trip to Vegas, I can put in it's location and RSS readers will know that it was about Vegas.  The same goes for all of my Pittsburgh posts.  Outside.in is creating maps to display areas that are blogged about the most and where they are coming from, and they taking that data and laying it over google maps.  It's a pretty neat iniative.