Google Latitude Gets Checkin/Out

The Google mobile application for the Android and now for the IPhone called Latitude allows you to share information about you and any group on the Web.  Had always thought it would be good for mobile service and work groups.  The newest version of Latitude allows you to check in and out of locations as well.  Similar to location services like Foursquare.  Had examined these as methods to link with loyalty programs online.  A quick look at Latitude for the IPhone shows that there are now many options available, such as automatic check in.   It also allows a number of privacy options.  Despite the fact that this was an early location based system,  I have seen relatively few examples of it in use.  Any enterprise examples?