Update — Winter 2013: The spot got torn down. Nothing to skate here anymore.
Both sides of this building have an array of brick banks spouting up from the ground. Each one can be skated in a variety of ways: as a generic bank, as a means to stall on wooden benches that stem from some of the banks, as bumps, launches, etc. The better, smoother ones are on the 46th Street side. There are subway grates in the ground here and there, so you will have to work your way around them in order to gather up speed, depending on which part of the spot you’re skating.
Bust — ♦♦♦ / Half-and-half: This spot is best skated at night. Throughout the day, there are usually people sitting on the benches. At night, there may be crackheads sleeping on certain obstacles. You have a slight chance of getting kicked out by security, but they typically do not bother you.
Location: 47th Street or 46th Street (they’re on both sides of the building) and Third Avenue. Take the 4, 5, 6 or 7 to 42nd Street-Grand Central, skate east on 42nd until you reach 3rd Avenue, make a left, and skate north for four blocks.
Pictures (Click to Enlarge):