  We perform a wide parameter space search for continuous gravitational waves
over the whole sky and over a large range of values of the frequency and the
first spin-down parameter. Our search method is based on the Hough transform,
which is a semi-coherent, computationally efficient, and robust pattern
recognition technique. We apply this technique to data from the second science
run of the LIGO detectors and our final results are all-sky upper limits on the
strength of gravitational waves emitted by unknown isolated spinning neutron
stars on a set of narrow frequency bands in the range 200-$400 $Hz. The best
upper limit on the gravitational wave strain amplitude that we obtain in this
frequency range is $4.43\times 10^{-23}$.
