  The smallest spot in optical lithography and microscopy is generally limited
by diffraction. Quantum lithography, which utilizes interference between groups
of N entangled photons, was recently proposed to beat the diffraction limit by
a factor N. Here we propose a simple method to obtain N photons interference
with classical pulses that excite a narrow multiphoton transition, thus
shifting the "quantum weight" from the electromagnetic field to the
lithographic material. We show how a practical complete lithographic scheme can
be developed and demonstrate the underlying principles experimentally by
two-photon interference in atomic Rubidium, to obtain focal spots that beat the
diffraction limit by a factor of 2.
