  We theoretically consider the phenomenon of field-free long-lasting
orientation of symmetric-top molecules ionized by two-color laser pulses. The
anisotropic ionization produces a significant long-lasting orientation of the
surviving neutral molecules. The degree of orientation increases with both the
pulse intensity and, counterintuitively, with the rotational temperature. The
orientation may be enhanced even further by using multiple delayed two-color
pulses. The long-lasting orientation may be probed by even harmonic generation
or by Coulomb-explosion-based methods. The effect may enable the study of
relaxation processes in dense molecular gases, and may be useful for molecular
guiding and trapping by inhomogeneous fields.
