  We show that circularly polarized femtosecond laser pulses produce field-free
alignment in linear and planar molecules. We study the rotational wavepacket
evolution of O$_2$ and benzene created by circularly polarized light. For
benzene, we align the molecular plane to the plane of polarization. For O$_2$,
we demonstrate that circular polarization yields a net alignment along the
laser propagation axis at certain phases of the evolution. Circular
polarization gives us the ability to control alignment of linear molecules
outside the plane of polarization, providing new capabilities for molecular
imaging.
