It is legal to keep beehives in the city (just make sure you follow the proper registration process and rules.)  A great source of information can be found on the New York Beekeepers Association website.

Bees are kept on rooftops, in backyards and tucked into community gardens throughout the five boroughs.  A couple times a year you might see a few individuals donning their veiled hats along with gloves and pants tucked into their socks making their way around the city getting ready to extract some honey.

The process can become a spectator event but learning about how to harvest honey and getting to sample the results is worth sticking around.

One beekeeper told me the hive they were harvesting from would yield about 40 pounds of honey!  And that is after leaving more than half of the honey in the hives for the bees to and continue to add to for their winter stores.