WNYC just created a fantastic transit calculator map for travel time from borough to neighborhood to zipcode in New York City. Just type in a desired address, and you can see average travel times to anywhere in the five boroughs. This is my average travel-time living on East Broadway on the Lower East Side. The red colors indicate a less than ten minute commute, ranging from purple showing over and hour and a half travel time.
This is a great tool if you're looking for a new apartment in a new neighborhood, but aren't sure about how long you'll spend in transit during your work commute.