NYC for people flying into town is accessible via any of the 3 major airports in the area: LGA, JFK and NWK. LGA is closest to the main Columbia University campus, just about 20 minutes, but services mostly domestic flights. From LGA, one can take the M60 bus directly to CU, Amsterdam and 116th Street; and from JFK, one may take the A train (express) to 59th Street then transfer to the 1 (local) train to the 116th stop. For travelers coming in through NWK, there is a train from NWK to Penn. Station; from there, take the 1 train (local) to 116th Street (the express 2/3 is under maintenance during this weekend). See below for more detailed MTA directions.
Of course, cabs area available from any of those airports (but from NWK, it will be very pricey).
For other travel options, see Columbia's page.
Columbia University is easily accessible via public transportation. The use of the subways, trains and buses of New York City for the conference is strongly encouraged. See the MTA's website.
The university located on the Upper West Side of Manhattan, at 2960 Broadway and West 116th Street. One may view directions published by the university here: http://www.columbia.edu/about_columbia/directions.html.
NYCBSDCon will be held at Davis Auditorium on the main campus. Directions to the auditorium may be found here: http://www.cs.columbia.edu/theory/directions.html.
As an aside, one may also use hopstop to aide in navigating their way here.