Distributed Human Computation (DHC) holds great promise for using computers and humans together to scaling up the kinds of tasks that only humans do well. Currently, the literature describing DHC efforts so far is segmented. Projects that stem from different perspectives frequently do not cite each other. This can be especially problematic for researchers trying to understand the current body of work in order to push forward with new ideas. Also, as DHC matures into a standard topic within humancomputer interaction and computer science, educators will require a common vocabulary to teach from. As a starting point, we offer a taxonomy which classifies and compares DHC systems and ideas. We describe the key characteristics and compare and contrast the differing approaches.