Keep your distance from old people, too. They are the first to call the cops, if they know what you are doing. Don't smoke a pipe in public. People will think you are smoking crack. And you don't want to get sly looks while your getting high.
Pipes are only acceptable in large parks and cars.
No playgrounds, leave them to the crackheads. Don't try to roll a joint on the far east or far west sides of Manhattan the wind will blow your stash to New Jersey or even worse, Queens. Fourth between Broadway and Lafayette on the North side of street. Do not smoke on 14 Street, 42nd Street, or 57th Street. Too many people with anti-pot attitudes.