In the interest of sorting out helpful information in aftermath of Hurricane Sandy, here are a few links:
The New York Times has a page combining news updates with a handy list of which services (electricity, transportation, emergency supplies) are currently available (or, in the case of several transportation options and utilities, not currently available). Also at the New York Times, the City Room blog has a list of volunteer and aid opportunities.
The Federal Emergency Management Agency has a resource page to donate and find volunteer opportunities. (Link includes resources in various northeastern states as well as New York City.)
NY Tech Meetup and New Work City are working to help local businesses and organizations get their technology up and running. If you can help (or can identify someone who needs help), let them know.