Gulfport has Airtran,northwest,atlantic southeast(Delta co.),continental. All are jets. Mobile has Delta, airtran, us airways and a few others and is only a 45 mintue drive from Biloxi. New Orleans of course has everything and you can make it to Biloxi within 2 hours.

Air Tran connects out of Florida and Atlanta
Northwest out of Memphis
Continental out of Houston
Atlantic SE out of Atlanta.