They seem to have also invented the concept of "checking-in". See video[1] at 0:38 second mark onwards where he talks about a student checking in at Guatemala.

They seem to have also invented the concept of "checking-in". See video[1] at 0:38 second mark onwards where he talks about a student checking in at Guatemala. [1]http://www.youtube.com/watch?v=3WdS4TscWH8 http://www.youtube.com/watch?v=3WdS4TscWH8