I agree on the pen thing. I have a very expensive German made pen that is very heavy and I could easily stab someone quite deeply with the pointy end, or hit a pressure point with the other, as well as do minor grappling with it. Metal pens can be very very strong. There's a reason tessen were so popular with police in the 1800's in Japan!
Check your state laws. Another weapon that I carry is a hissatsu 'tactical' knife which is REALLY long and probably not legal to carry in New York. Nevertheless, check it out, because if you are able to carry it (concealed) that kind of weapon will end most confrontations very quickly. Very durable, thick metal, and meant for fast kills. Here's a pic..http://images.military.com/pics/SoldierTech_Hissatsu4.jpg
The blade is huge though and probably not legal to carry concealed.
If you can't have one of those, there are also jutte which are kind of like old fashioned police batons. Same purpose anyway, generally nonlethal, can be used for very hard grappling, striking and you can throw them at someone. If you are trained at throwing things like axes or shuriken you could probably throw one deep into someone through a few layers of clothing if the end is tapered/sharpened.
You should always have 2 weapons on your person, one nonlethal and one lethal. Use whichever one you think is most appropriate if the excrement hits the rotary.