  We give a brief overview of recent results obtained through the gauge/gravity
correspondence, concerning the propagation of a heavy quark in strongly-coupled
conformal field theories (such as N=4 super-Yang-Mills), both at zero and
finite temperature. In the vacuum, we discuss energy loss, radiation damping,
signal propagation and radiation-induced fluctuations. In the presence of a
thermal plasma, our emphasis is on early-time energy loss, screening and
quark-antiquark evolution after pair creation. Throughout, quark dynamics is
seen to be efficiently encapsulated in the usual string worldsheet dynamics.
