Originally Posted by sam123

Don't go outside security.

There are AA self-service kiosks near gate 42.

Also, like flyer23 said, you can just go to your departure gate and check in with the gate agent. I've done it, last time a week ago in BOS on a UA MR with 1hr turn time after a red-eye. The agent may be curious on how you got there, just tell em! In my case she laughed, printed my BP, and said: "You're even crazier than I am!"

Sami