High quality locomotion is key to achieving believable character animation, but is often modeled as a generic stepping motion between two locations. In practice, locomotion often has task-specific characteristics and can exhibit a rich vocabulary of step types, including side steps, toe pivots, heel pivots, and intentional foot slides. We develop a model for such types of behaviors, based on task-specific foot-step plans that act as motion templates. The footstep plans are invoked and optimized at interactive rates and then serve as the basis for producing full body motion. We demonstrate the production of high-quality motions for three tasks: whiteboard writing, moving boxes, and sitting behaviors. The model enables retargeting to characters of varying proportions by yielding motion plans that are appropriately tailored to these proportions. We also show how the task effort or duration can be taken into account, yielding coarticulation behaviors.