Source localization using a network of sensors is a classical problem with applications in tracking, habitat monitoring, etc. A small number of transmitters in the plane broadcast sine waves, a small number of receivers record the signal, and we want to recover the transmitters' locations from the receivers' observations. A solution to this estimation problem must satisfy a number of competing resource constraints, such as estimation accuracy, communication and energy costs, signal sampling requirements and computational complexity. This paper exploits recent developments in sparse approximation and compressive sensing to efficiently perform localization in a sensor network.