I met people at most of the hostels I stayed in elsewhere, but HINY has a lot of school groups so it was less friendly. The YMCA in Harlem has a small common room but people mostly use it for wifi so don't chat- though the staff do. I found though that I met people in cafes, queues, trains, galleries etc- in fact almost anywhere I stood still. If you are in NY for a while, your best bet is to go to the places that interest you and you are bound to meet friendly locals.
Pro tip
