With the rise of social media platforms, crowdsourcing became a powerful tool for mobilizing the public. Events such as the earthquake in Haiti or the downfall of governments in Libya and Egypt indicate its potential in crisis situations. In the scope of this paper, we discuss the relevance of crowdsourcing in the area of crisis and disaster management (CDM). Starting with a general overview of the topic, we distinguish between different types of crowds and crowdsourcing and define what is meant by crowdtasking in the area of CDM. After considering technological, societal and ethical challenges for using crowdsourcing in crisis management, applications of crowdsourcing tools in ongoing projects are described and future developments outlined.