http://www.skybrary.aero/
SKYbrary is an initiative of EUROCONTROL, ICAO, and The Flight Safety Foundation aimed at developing a comprehensive source of aviation safety information and making it available to users worldwide.
SKYbrary's objective is to become the single point of reference in the network of aviation safety knowledge. The SKYbrary knowledgebase is a dynamic enterprise and we envisage that this will take 3 years to achieve, and will require the support and active participation of all those interested in promoting best practice and knowledge in aviation safety.
Wiki-based flight safety site. Seems to be a promising concept, provided the site attracts enough contributors from the professional aviation community.