If you like to shop, then take the train from the airport to suburban station, take the 17th or 18th street exits (can be confusing - but look for signs) and walk a few blocks south to Walnut Street. On Walnut street between Broad (14th) and 18th streets is a lot of high-end shopping. The area around 18th and Walnut is also home to a large French population, so there are several great cafes as well. If you are a coffee lover, I recommend La Colombe at 19th and Walnut.