GeoMeme is the first Google Maps mashup I've seen to use the Google Buzz API.
GeoMeme is a fun way to measure and share real-time local Twitter (and now Buzz) trends on a Google Map. Using the map it is possible to view Tweets from any location in the world. Positive Tweets are streamed on the left of the map and negative Tweets from that location are streamed on the right.
I can inform you that at the time of writing Love is beating Hate in New York.