In this talk I will discuss some aspects of: (1) passive locomotion and stability in unsteady flows; (2) motion synchronization in a finite dipole dynamical system; and (3) transient dynamics in viscously decaying point vortices. The emphasis throughout the talk will be on a low-order modeling and computational approach. A main theme connecting these projects, and one of the underlying motivation, comes from understanding the role of fluid-structure interactions in fish locomotion and fish schooling.