Velocity fields are an integral part of many computer graphics applications, such as fluid animations, wind fields, and as guides for animated characters. In practice, the use of velocity fields in interactive environments is limited by the expense of storage and the difficulty of designing fields to satisfy boundary conditions and other properties. In this talk I describe flow tiles, a novel approach to designing and evaluating velocity fields. A flow tile is a small region of flow. Large fields can be created by tiling a set of prototypical flow tiles, much as computer games create terrain by combining terrain tiles. The advantages to tiling include efficient computation and memory usage, interactive design of large fields, and easy embedding into virtual environments. Three applications are presented: a river flow, characters guided through city streets, and swirling fog.