How can I find quick work to make some money (legitimately and in person, not online) in NYC within the next week?

Within a week is tough. With your skills you can try registering with temp agencies (they pay weekly the week following the work). I don’t know how they have been affected by the bad economy.

You won’t get that much, but you can sell plasma if you are healthy.

Here in California, we have agencies that cater to Day workers and they supply workers to offices or other businesses. The best way to make really fast money is to sell some of your belongings, or beg.

Ask your grandmother, that’s what my adult grandsons do.

Can you play an instrument of any kind? There’s always busking. Cater-Waitering is another one that gives you quick cash, just not a lot. Most temp agencies have hookups to those jobs. As a perk, you might see one of your idols at a dinner party or fundraiser. Exciting stuff.

Try waiting on tables but just not catering at an hourly wage.
Find an entry level position in a busy place downtown. There are thousands of restaurants and the possibility to make 200 bucks a night or better is very achievable. The right place and you can make serious coin. 150.00 bottles of wine, 16.00 martinis and watch the tab go up.
A 20% gratuity on a 1500.00 dinner tab? Do the math. Take a look at the classifieds but don’t be afraid to show your face. Just walk around before dinner rush 3–4, walk in doors and shake some hands. And it shows you’ve got moxie to a manager. Turn over is rapid and even if you don’t get a hit at one place, you’ll get leads. People in the business know each other. Best of Luck.