  We show that the recently demonstrated technique for generating stationary
pulses of light [Nature {\bf 426}, 638 (2003)] can be extended to localize
optical pulses in all three spatial dimensions in a resonant atomic medium.
This method can be used to dramatically enhance the nonlinear interaction
between weak optical pulses. In particular, we show that an efficient Kerr-like
interaction between two pulses can be implemented as a sequence of several
purely linear optical processes. The resulting process may enable coherent
interactions between single photon pulses.
