Hurricane Hackers have mobilized very quickly to respond to Sandy. Check out their resources here:

• Web site: http://www.hurricanehackers.com/
• GitHub: https://github.com/HurricaneHackers
• Twitter: @hurricanehackrs
• Email list: hurricanehackers@mit.edu
• Internet Relay Chat: http://irc.lc/freenode/hurricanehackers