Mark van Embden Andres discusses Elva (www.elva.org), a free, open source online platform that allows organizations to map local communities' needs using web and mobile phone technologies. From monitoring elections in Tunisia, surveying community safety in Kosovo to assessing solid waste management in India, Elva's projects involve a wide variety of participants from different cultural, ethnic and social backgrounds. The crucial element in making crowdsourced crisis management work is not the development of a platform itself, but to engage local communities in a meaningful, mutually beneficial way and - even more importantly - to keep them engaged over the longer term. To achieve this challenging goal, Elva developed a Social Engagement Kit (SEK), a set of guidelines for effective citizen engagement. This powerful collection of lessons learned includes brief guidelines on social practices and tech development standards that make it easier to get high citizen participation rates (e.g., how to select participants, how to approach them, what incentives to provide, how to make tools responsive to users, how to build a sustainable dialogue and how to best provide feedback on achieved results). The Talk will highlight some of the most important examples and lessons learned from the SEK.