...how are they going to verify that people are really in a high school, given that most people don't have an e-mail address that connects them to their high school....?
Huh. The college and high school sites are completely separate. Nobody in high school can search for you, see your profile or even send you a message. You can't interact with them either, but you can help your friends in high school get on facebook by inviting them to join.
Righty then... I've got 7 invites.