Hop on a train into Center City. Munch on a soft pretzel for a morning bite. Take a look at the line for the Liberty Bell and keep walking (unless you've got a whole bunch of time
) Head to South Street, do some serious shopping. Go to Pat's, buy a cheesesteak for lunch.
And then? Somebody else can fill in this point, because by this time I can be found at the Plow and Stars in Olde City, downing a Guinness
Oh, be sure to file a trip report for your PHL-LGW flight; I'm flying US Airways transatlantic on an A330 for the first time on Sep 17th and have no idea what to expect