AirTran is having a sale on many of it's fares until 10/9/03. I just booked from South Florida to Atlanta for $75 a leg.
"... through October 9, 2003, all AirTran Airways destinations are on sale. These special fares are good for travel all the way through February 5, 2004. Fares require a 7-day advance purchase and are not valid on Sundays."
Another good one - Delta has specials and fan-fares weekly, but it's ALWAYS short notice (same week - so much for planning). The prices can't be beat, though (often $118 round-trip from SoFL to Atlanta).