Microblogging services such as have become popular venues for informal information interactions. An important aspect of these interaction is question asking. In this paper we report results from an analysis of a large sample of data from Twitter. Our analysis focused on the characteristics and strategies that people bring to asking questions in microblogs. In particular, based on our analysis, we propose a taxonomy of questions asked in microblogs. We find that microblog authors express questions to accomplish a wide variety of social and informational tasks. Some microblog questions seek immediate answers, while others accrue information over time. Our overarching finding is that question asking in microblogs is strongly tied to peoples' naturalistic interactions, and that the act of asking questions in Twitter is not analogous to information seeking in more traditional information retrieval environments.