How can I find a good (local) electrical engineer
I don't know of a good site devoted to contract jobs for EEs.

You might try talking to folks at NYC Resistor. They're a hacker collective, not an EE company, but they're in Brooklyn and might know local EEs.

You might also ask in the Adafruit forums. Adafruit is based in New York. While the customers are from all over the place, you might find more New Yorkers than here. (Chiphacker seems to have a lot of folks from Australia and the UK.)

Here are a few examples of folks who could probably do the job (but they're in California): 


mindtribe.com
219design.com
speckdesign.com
d2m-inc.com


You might also want to think about whether you have the resources to hire an electrical engineer to work for you. Very few individuals do. The going rate for consulting engineers in New York is probably above $100/hour, and developing a real product takes at least hundreds of hours.