If you're planning a trip for fall, keep your eyes open as we're seeing more sales for the period. To qualify for this one, you must buy before July 15 and travel between Aug. 23 and Dec. 14. Sale fares are not valid Fridays or Sundays and blackout dates are Sept. 1-5 and Nov. 17-29. Here are some sample one-way fares from Boston: Philadelphia for as low as $39; Baltimore $54; Raleigh/Durham $79; Pittsburgh $89; Denver $129; Long Island $138; Chicago $151; Kansas City $153; Oklahoma CIty, El Paso, and St. Louis $179.
And here is all the fine print.