It’s quite easy these days to geo-tag blogs posts, photos, comments, and other bits of data and then display them on a map. The comments geo map plugin I made a few years ago did just that for comments and allowed a conversation to have an added geographic dimension.
I just came across the way Gothamist does this with what they call a News Map:
I think this would be a great way to list stories on Streetsblog.org, Streetsblog.net, Streetfilms and also GothamSchools as an alternative to the reverse-chronological blogging format. The map could position itself by default at the location of the user to show them stories immediately surrounding them. The sidebar could display a reverse-chronological list of blog posts. When you click on a title it will highlight the blog post on the map.