Apple has updated the Find My Friends functionality on iOS 6 to include location based alerts.
This can come handy for families where they can track the location of each other. This can also come handy for friends who meet on a regular basis and need to find out where the other guys are.
Apple described the update:
Find My Friends is a great way to share locations with friends and family. Those who share their locations with you appear on a map so you can quickly see where they are and what they’re up to. And with iOS 6, you can get location-based alerts — like when your kids leave school or arrive home. Find My Friends can also notify others about your location, so you can stay connected or keep track of the ones you love.