With only 7 hours to kill... I would suggest going out to eat!

If you want to go into manhattan

take the AirTrain, take NJ Transit or Amtrak (your preference) to New York Penn Station, that will put you at 31/32 street and 7th / 8th ave you can go to a variety of places no more than 10 dollar cab ride. Personally I LOVE Eatry ( a bit up town), Cafeteria (in Chealsa), or the world famous Serendipity 3 ( a bit up town)...
You're also be very close to Macy's Herald Square or Bloomingdales is at 59th and lexington...

Time Square is not far away with two movie theatres, AMC and Lowes, but there is the Lowes 34th Street near Penn Station which is very nice...

If you want good Spanish or Portugese food...
Take the AirTrain to Newark Penn Sation...

take a cab to either Don Pepe, or Spanish Tavern...

Not much else to do in the newark area...

PVT me if you want more info...

-Vincent