The founders of Ushahidi and the team that supports the multiple deployment of the platforms around the world, have given crisis mapping and crowdsourcing during emergencies their "lettre de noblesse" ... their title of legitimacy of sorts.
Whether in Haiti or in Japan, the use of the Ushahidi/Swiftriver/crowdmap set of tools has made a real difference in the response and recovery phase. If social media is about empowerment of the citizens ... turning witnesses and victims into participants, then Ushahidi is about giving them the tools to make a valuable contribution that can be legitimized and integrated into emergency management programs around the world.
Of particular interest for emergency managers is the analytical tools offered by Swiftriver that allow real-time evaluation and validation of social media and other info.
For its key role in advancing the use of social media, crowdsourcing and crisis mapping in disasters, the Ushahidi nexus ranks at 16 on my list.
The list so far:
#16: ushahidi ... witnessing change and progress in SMEM