Here's quick overview on Facebook Places (Facebook's new location-based service) from David Armano.
Key pull quote from David:
"From a user perspective, Facebook places is not bad, which is a bit of an accomplishment for a new launch. From a platform perspective this is not great news for the competition. However, there are some serious issues and the biggest is lack of integration with other platforms such as Twitter. There is also no reward system (badges) which some Foursquare users like and others care less about. The experience though shows promise and for Facebook it's yet another source of behavioral data which will prove to be valuable to advertisers and brands. In short, as a user it's off to a decent start. If your Facebook connections use it, it's likely you might as well. If users adopt the behavior as Facebook rushes to support other mobile platforms and global locations it could gradually make the act of checking-in as common as the status update. If this happens, organizations with physical locations will have to take a very close look at this and what it means for their business."