Fly Southwest for as low as $49 O/W
Southwest Airlines is offering $49 O/W (plus taxes and fees) between Philadelphia and the following cities:
Columbus, OH
Manchester, NH
Pittsburgh, PA
Providence, RI
Raleigh/Durham, NC
Booking which is open until Thursday, May 31 and travel is valid through the 2nd of November 2007.
You can also take advantage of their 14-day advance purchase which would reduce fare cost to $29.