For your convenience, most airlines at Phoenix Sky Harbor offer self-service check-in kiosks. Even if you are checking luggage, the self-service option can be more than twice as fast as waiting in line for a customer service agent.
Not checking a bag? You may be able to bypass the ticket counter level altogether. Look into printing your boarding pass before you come to the airport. Some airlines also offer self-service kiosks near the security checkpoints.
Visit your individual airline web site for further information.