You definitely need an appointment to use the Passport office. Usually they say that you should only come in to the office if travelling within 14 days, but I don't know how closely (if at all) they enforce that policy:


http://travel.state.gov/passport/abo...ncies_912.html


http://travel.state.gov/passport/fri/add/add_850.html

http://travel.state.gov/passport/for...4085_2662.html




Here is the form to use for the extra pages:

http://foia.state.gov/FORMS/Passport/DS4085.pdf


As you can see on the instructions, when using the mail service, there is only a fee when requesting expedited service. I would call the NY facility to ask whether the fee will be charged for a walk-in request.