Two individuals have a regular task to complete that requires the effort of only one. Some days it is less costly for one of the individuals to complete the task, and some days it is less costly for the other individual. Each knows only their own cost. Taking turns is fair, but rigid turn-taking cannot account for changing costs. The person obligated might not be best suited for the job. A natural solution is to allow some flexibility - swapping turns when efficient. These arrangements are so familiar, we rarely think of them as economic mechanisms, but doing so provides interesting insights into their properties and performance. In the first chapter of this dissertation, I model flexible turn-taking as a simple dynamic mechanism (recurring rotation) and derive theoretical properties of the mechanism. In the second chapter, I present results of an experiment designed to test these properties. Although the efficiency achieved by subjects is close to the expected efficiency, behavioral anomalies that cannot be explained by social preferences or strategic concerns suggest that subjects may be used to a different form of flexible turn-taking. An alternative form of flexible turn-taking (obligation takeover) retains familiar structure, is consistent with patterns of subject behavior, and can achieve approximately the same efficiency as an optimal mechanism using money transfers under uniformly distributed costs. I present this in the third chapter.