Facebook has released data based on check-ins and third-party location services that have integrated with the Facebook Places API, but only for airports around the world. It turns out that the Los Angeles International Airport is the most social out of the world's airports, as it has the highest number of check-ins to the social network between August 2010 and November 2011. In other words, more people share that they are at LAX than any other airport in the world.
The data also shows that checking into airports via Facebook is a largely US phenomenon. Out of the top 25 list of airports, which you can see below, only five were not located stateside:
Four months ago, Facebook decided to kill Facebook Places. In its place though, Palo Alto added a lot more location features to its social network. Although it phased out the mobile-only Facebook Places, the company started letting users add their current location to anything (status update, photo, or Wall post), from anywhere (regardless of what device you are using).