Crisismappers are online teams of people who gather and provide data online to people responding to and people caught up in disasters.
Crisismapping has been around for a while, but for most people it started with the 2010 earthquake in Haiti, where all the government and NGO information needed to respond to the earthquake was lost in the earthquake. We created online maps from satelllite images, put SMS and media reports onto an Ushahidi map, got documents into Sahana, added the details of people who were lost into Google's People Finder tool, built websites and software to help, and did dozens of other small data jobs that made a difference to what was available online and in the country (we even sent data updates into the country on USB sticks). Since then, we've mapped in places like Libya (refugees), Japan (tsunami), Chile (earthquake), Pakistan (floods), Somalia (refugees), Alabama (tornadoes) and been ready to help with dozens of other crises around the world.
Crisismappers are usually volunteers: many of them are highly-skilled both at data gathering, mapping and analysis, and in areas which impact this work (like open-source technologies), but if you're new to crisismapping, don't let that put you off joining in: everyone starts as a newbie sometime, and many of those skills were gained through hours of working on maps.
This meetup is open to anyone working on crisismapping, working with crisismappers or interested in crisismapping in general. Please come join us! We'll try to hold a meetup once a month if we can (getting venues in NYC is always a problem) - pub and date suggestions are also welcome if you just want to hang out with other mappers too (we usually collect up in the Coffee Shop bar on Union Square).
If you want to know more about crisismapping, these places might help.