I just heard about this site on the most recent Boing Boing podcast called
outside.in it's just about the coolest new website idea I've heard of in the last while. Essentially it's a page that links information people have posted on there blogs (or directly on the site) to a google map. So if you center the map on your neighborhood, you'll see general posts about what's going on in that area, what people are talking about etc. You can also filter posts by subject matter, politics, art etc. It's worth visiting to really get what it's doing and what makes it different then a simple local happenings webpage.
Unfortunately it's US only right now (booo!) but I'll try putting it to the test when I'm in San Francisco in December.