Hitchsters
Taking a Taxi is not exactly what budget travelers do. But there are instances wherein you are left with no other choice. You may have way too many luggage, it's just way too inconvenient, you are too tired and/or you just cannot figure out how to get to/from the place where you will be crashing in to/from the airport.
So yes, taxi, it has to be.
Now, if you find yourself in Manhattan or Brooklyn, you have another choice… Hitchsters, the best way to share a ride to and from the airport.
All you have to do is to enter your flight details or the time you intend to hail a cab. The database will then match you with a co-rider (usually, they choose people who are/will be on the same flight). You will get an info by text message about your co-rider. You can then contact each other to coordinate.
Since hitchsters is a free service and anyone can easily register, you have take a bit of risk. Make sure that you read the faq and safety guidelines to prepare yourself for any eventualities.