Originally Posted by
chariot
Do allot additional time if you happen to be heading to jfk on a fri evening as traffic to jfk from the city can be quite bad. Another option for your return that could be convenient (esp if you're flying DL) is to take the helicopter in from downtown or midtown. You can book them in advance, it takes 8min and costs ~$165
http://www.flyush.com/
If the OP is traveling on a Friday, a cab ride out to JFK could easily take one hour or more. If the $165 for the helicopter is too pricey for the OP (assuming he/she goes into Manhattan), I would opt for the LIRR to the Airtrain. At least the time to the airport would be more predictable and the trip would of course cost less.