  We present a coincidence search method for astronomical events using
gravitational wave detectors in conjunction with other astronomical
observations. We illustrate our method for the specific case of the LIGO
gravitational wave detector and the IceCube neutrino detector. LIGO
trigger-events and IceCube events which occur within a given time window are
selected as time-coincident events. Then the spatial overlap of the
reconstructed event directions is evaluated using an unbinned maximum
likelihood method. Our method was tested with Monte Carlo simulations based on
realistic LIGO and IceCube event distributions. We estimated a typical false
alarm rate for the analysis to be 1 event per 435 years. This is significantly
smaller than the false alarm rates of the ndividual detectors.
