A general word of advice: When you rent a car at any airport, you pay airport facility fees and security charges that only apply to airport rentals--even though you're only on airport property for a little while. It can run to $15/day over and above the rental fee.

My advice: If you can arrange it, rent a car at an off-airport facility, even if it means you have to take a bus or taxi from the airport to those offices. You can easily find those offices by searching the car rental companies' websites.

DiMaggio, if you're planning to stay in an inexpensive place in NYC, you'll probably be staying in Queens or Staten Island--no cheap places in Manhattan. Taking the subways is the best way to go. But if you plan to visit places in the outer boroughs, it might pay to rent a car. Subway and bus service in the outer boroughs isn't real convient.