- BA offers Concorde passengers free helicopter transfers between JFK and LGA. Not too useful as JFK-LGA is generally a cheap and quick taxi ride anyways.

- There are no scheduled flights but several helicopter companies offer charter flights between midtown and JFK. Cost is $595 flat, and the helicopter can carry upto 4 passengers.

(Somehow I don't think that I could put down on my expense report:
JFK-Midtown helicopter - $595
without attracting undue attention

And kappa, London is the "city" as well.