  The EGRET catalogue of unidentified X-ray sources has more objects along the
galactic disk than at high galactic latitude, where identifications are
comparatively easier. On the other hand, the Egret/GRO mission has already
identified several known radio pulsars as gamma-ray sources as well as
discovering Geminga's nature as a pulsar. If Geminga is not a unique case, as
it is very likely not to be, than other galactic sources could, in fact, be
radio quiet isolated neutron stars. For these, the identification work is
extremely difficult and should anyway start from high resolution X-ray/optical
data.
