  We present the results of a 5 GHz survey with the Very Large Array, designed
to search for short-lived (<1 day) transients and to characterize the
variability of radio sources at milli-Jansky levels. A total sky area of 2.66
deg^2, spread over 141 fields at low Galactic latitudes was observed 16 times
with a cadence sampling timescales of days, months and years. Most of the data
were searched for transients in near real time. Candidates were followed up
using visible light telescopes (1-2 hr delays) and the X-Ray Telescope on board
the Swift satellite. The final processing of the data revealed a single
possible transient with a flux density of 2.4 mJy. This implies a transients,
>1.8 mJy, sky surface density of 0.039 (-0.032/+0.13) deg^-2. This areal
density is consistent with the sky surface density of transients from the Bower
et al. survey extrapolated to 1.8 mJy. Our observed transient areal density is
consistent with a Neutron Stars (NSs) origin for these events. Furthermore, we
use the data to measure the sources variability on days to years time scales,
and we present the variability structure function of 5 GHz sources. The mean
structure function shows a fast increase on ~1 day time scale, followed by a
slower increase on time scales of up to 10 days. On time scales between 10-60
days the structure function is roughly constant. We find that >30% of the
unresolved sources brighter than 1.8 mJy are variable at the >4 sigma
confidence level, presumably due mainly to refractive scintillation.
