  We employed the SERENDIP III system with the Arecibo radio telescope to
search for possible artificial extraterrestrial signals. Over the four years of
this search we covered 93% of the sky observable at Arecibo at least once and
44% of the sky five times or more with a sensitivity of ~3E-25 W/m2. The data
were sent to a 4 million channel spectrum analyzer. Information was obtained
from over 1E+14 independent data points and the results were then analyzed via
a suite of pattern detection algorithms to identify narrow band spectral power
peaks that were not readily identifiable as the product of human activity. We
separately selected data coincident with interesting nearby G dwarf stars that
were encountered by chance in our sky survey for suggestions of excess power
peaks. The peak power distributions in both these data sets were consistent
with random noise. We report upper limits on possible signals from the stars
investigated and provide examples of the most interesting candidates identified
in the sky survey. This paper was intended for publication in 2000 and is
presented here without change from the version submitted to ApJS in 2000.
