The Internet is widely valued for distributing control over information to a lateral network of individuals, but it is not clear how these networks can most effectively organize themselves. This paper describes the distributed networks of volunteers that emerged online following Hurricane Katrina. Online communities responded to the disaster by facilitating the distribution of donated goods from ordinary people directly to hurricane survivors. These "connected giving" groups faced several challenges: establishing authority within the group, providing relevant information, developing trust in one another, and sustaining the group over time. Two forms of computer-mediated connected giving were observed: small blog communities and large forums. Small blog communities used a centralized authority structure that was more immediately successful in managing information and developing trust, but over time, blog communities were difficult to sustain. Larger and more decentralized forums had greater difficulties focusing the community?s communication and developing trust but sustained themselves over a long period of time.