The sense of commitment is a fundamental building block of human social life. By generating and/or stabilizing expectations about contributions that individual agents will make to the goals of other agents or to shared goals, a sense of commitment can facilitate the planning and coordination of actions involving multiple agents. Moreover, it can also increase individual agents' motivation to contribute to other agents' goals or to shared goals, as well as their willingness to rely on other agents' contributions. In this paper, we provide a starting point for designing robots that exhibit and/or elicit a sense of commitment. We identify several challenges that such a project would likely confront, and consider possibilities for meeting these challenges.