This is assuming his first flight is on time which is, unfortunately, not an assumption we should make. Oh what the hell! Let's pretend it is a fairy tale world where airlines actually keep the schedules they set.

If your friend has seven hours he could go to Manhattan but plan on a minimum of an hour to back to the airport and more if he has to travel at rush hour.

Olympia Trails runs buses ($11) to the World Trade Center and Port Authority Bus Station (for a few hours I would pick the former as it will be easier to get back to the airport...but that's just me).

Getting back there is always an option of avoiding the tunnel by taking the PATH subway train $1 (or something better the NY Waterways ferry - $2 - from the World Trade Center to either Colgate or Harborside - They are on either side of Exchange Place - five minute walk) to Exchange Place in Jersey City and catching a taxi there. It will cost about $30 to Newark Airport. I think it is more like $50 from the city.

The cheapest option is to take the PATH train to Penn Station in Newark and get the regular NJ Transit bus from there. Don't know how long this would take, but a guess would be a more than one hour.

If he goes to the World Trade Center he can easily walk to South St Seaport (from here he can take a 50 minute NY Harbour cruise for $12 - Statue of Liberty, Brooklyn Bridge, Ellis Island), Battery City Park, Wall St., Trinty Church and the World Trade Center itself.

I travel frequently from Newark and it is the most unentertaining airport I use. If your friend must stay there I suggest he take the train that connects the terminals to Term. C. It is the Continetal terminal and seems to have the best facilities. Terminal A is the worst.

Jude