Outside.in is another site that shows news, civic information and blogs posts relevant to a location. See the outside.in site for Catonsville MD, the area around UMBC for an example.
They recognize the location of a blog posts as follows. A blogger registers he feed with outside.in and they monitor the posts. She geotags blog posts with the a location using one of four methods: (1) a link to a Google map with the location, (2) a blog category or tag that looks like a Zip code, (3) an inline text tag like or [where 1000 Hilltop Cir, Baltimore, MD 21250], or (4) geoRSS