During our great training in November, we had some discussions on the use of social media and how it can impact and strengthen the work of nonprofits.
One of my favorite tools is Ushahidi. It is a great open source program created in 2008 to map violence in the post-election Kenya. It is currently being used to gather information on democratization processes, conflict prevention and so on. It was deployed in Congo to monitor unrest and in Gaza by Al-Jazeera.
It connects people through cell-phones and it allows for information to be shared fast.
For more information, please check out the TED Talk by Erik Hersman, one of the co-founders of Ushahidi: http://fellows.ted.com/profiles/erik-hersman
Also, for more information on Ushahidi: http://ushahidi.com/