A very common class of fluid-structure interaction problems involves the dynamics of flexible fibers immersed in a Stokesian fluid. In biology, this arises in modeling the flagella or cilia involved in microorganism locomotion and mucal transport, in determining the shape of biofilm streamers, and in understanding how biopolymers such as microtubules respond to the active coupling afforded by motor proteins. In engineering, it arises in the paper-processing industry, where wood pulp suspensions can show an abrupt appearance of normal-stress differences, and in microfluidic engineering, where flow control using flexible particles has lately been explored. Flow-induced buckling of fibers is an important determinant of fiber transport in these flows, as well as of the fluid mechanical stresses that develop.