And by downloading the location based Yelp and Toilet Finder apps, you will locate the Starbucks closest to you. If you are on the southwest corner of 42nd and Lexington, for example, looking north, and open your Yelp App and search "coffee shops", it will send you to the Starbucks on Lex between 42nd and 43rd. My guess is if you are on the southeast corner of 42nd and Lex it will say 0.1 mile.
With these Apps, you can walk anywhere in NYC and there will probably be a toilet within .1 or .2 miles with directions available from your App if you can't figure it out based on how the City is plotted.
Another trick if you lose track of east, west, north or south and are anywhere south of 42nd is to always look for the Empire State Building which I think is 34th and 5th or so. When you see the ESB look at the street you are on and it will tell you where you are and in what direction you should be walking. Obviously if you have a smartphone these Apps have links to GoogleMaps GPS and it will walk you there if the ESB "eye test" doesn't do the trick. The only areas where I tend to get lost is down in Soho and Nolita and I have used my Apps to get me on track a few times when I couldn't see the ESB. BTW- my avatar pic was taken in Nolita.
The Port Authority toilets should never be touched by your butt cheeks! Totally unnecessary experience.