Like drbala said you can pick up your ticket at the AA office at ARN. However, a word of caution, if you have more than 16 segments in your itinerary (including open segments) the AA computer will not print the ticket. The agent will have to either hand write it or trick the computer and split your booking into two (or more if you are over 32 segments). So, if you are planning on picking it up at the airport, make sure to allow at least an extra hour before your flight, and also note that the AA airport office is only open in the morning around the departure time of their Chicago flight.