: 
Let's
face it, if you're going to be out and about, it pays to be prepared. In
addition to the clean restrooms listed below, here's a general guide: If
you see a hotel, you pretty much breeze right in and find the loo (if you're
on West 44th Street between 5th and 6th Avenues, you have to check out the
lavatories in The Royalton Hotel). And the only upshot to Barnes and Noble
putting so many small booksellers out of business is that wherever you see
their sign looming, you can be sure that there are restrooms inside for
your use. Finally, generally speaking, police precincts are a good bet when
nature calls. Also, say it's really late at night, and the only places open
are the 24-hour diners, who all stipulate that "restrooms are for customers
only." Go inside and buy a paper cup for ten cents or so, which makes
you a customer, and then you're in.
A few more of Ken Kidd's picks :