Every day Foursquare users create millions of check-ins using the location-sharing platform. Those may be only a small fraction of the traffic seen by its API, which we've estimated receives at least 5 billion requests per month. The company continues to expand the local data made available via its API, so developers of all sorts are finding it a rich resource for building their apps.
If the Queen of England used public transportation, she wouldn't have far to walk from her Buckingham Palace home. And finding her nearest stop is now very easy since Transport of London has implemented a Google Maps mashup of bus routes.