Knowing where everyone important to you is at any given moment no longer requires "eyes in the back of your head" the way it did for our parents. Thanks to apps like Apple's Find My Friends
iOS app (and voluntary "I am here!" apps like Foursquare and Facebook's check-in service), stalking (with permission) your friends and loved ones has never been easier. Bloomberg is reporting that Facebook will launch such an app
for iOS and presumably Android to offer the same abilities for your Facebook friends.