  It is well known that magnetic activity in late-type stars increases with
increasing rotation rate. Using inversion techniques akin to medical imaging,
the rotationally broadened profiles from such stars can be used to reconstruct
`Doppler images' of the distribution of cool, dark starspots on their stellar
surfaces. Interacting binaries, however, contain some of the most rapidly
rotating late-type stars known and thus provide important tests of stellar
dynamo models. Furthermore, magnetic activity is thought to play a key role in
their evolution, behaviour and accretion dynamics. Despite this, we know
comparatively little about the magnetic activity and its influence on such
binaries. In this review we summarise the concepts behind indirect imaging of
these systems, and present movies of the starspot distributions on the cool
stars in some interacting binaries. We conclude with a look at the future
opportunities that such studies may provide.
