  We argue that spontaneous Lorentz violation may generally lead to metastable
domain walls related to the simultaneous violation of some accompanying
discrete symmetries. Remarkably, such domain wall solutions exist for
space-like Lorentz violation and do not exist for the time-like violation.
Because a preferred space direction is spontaneously induced, these domain
walls have no planar symmetry and produce a peculiar static gravitational field
at small distances, while their long-distance gravity appears the same as for
regular scalar-field walls. Some possible applications of vector-field domain
walls are briefly discussed.
