$40+: Airfare sale to/from top US cities (one-way) Aug 12–Oct 31
Southwest Airlines
$110+: Reduced summer US airfares (round-trip) Through summer
Major Airlines
New Summer & Fall Fare Sales from $66 One-Way
Shermans' Review
$66+: Nationwide summer/fall fare sale (one-way) Through Nov 12
AirTran
$119+: Rock-bottom summer fares (round-trip) Through summer
Delta