Newark is quite a way from Manhatten and though most things in NY are 24 hours, plan your return carefully, as trasport servces are more infrequent at these later times. NY is full of 24 hour diners, so take your pick. Many serve alcohol as well, but nearly all will serve a wide range of foods to suit all tastes - and endless coffee and peoplewatching experience. The train from Newark gets in at Penn station, which is next to Maddison square gardens and within walking distance of the 24 hour cauldron that is times sqaure. if you are feeling brave, I would suggest getting the train into Manhatten. Walk up to Times Sq for a nose about, hail a cab and get him to take you to a diner on the riverside in Brooklyn. You can then watch the sunrise over Manahtten and the river and bridges. Use the internet to book a "car service" to take you back to the airport, perhaps by way of battery park to get a view of Miss Liberty and ground zero in the early morning light. Arrange to meet them in the foyer of any big hotel or at the station at a fixed time. You will find this a more reliable and cost effective way of getting to the airport (assuming there are more than one of you). Emjoy a bagel before you get back to the airport and you've done many of the main NY sights in a stopover.