A brief history of the search for extraterrestrial intelligence and an   appraisal of the future of this endeavor
  The idea that credible searches for Extra-Terrestrial Intelligence (ETI) could be carried out were laid out in detail in the (now classic) paper by Morrison and Cocconi (1959). They suggested using the radio band for these searches. Since then radio searches have been carried out by over sixty different groups. No signals from ETI's have been identified. Most searches did not have high sensitivity and it is not surprising that ETI signals were not detected. It is important to note, however, that these efforts were instrumental in developing new technical capabilities and they helped generate wide interest in this field. In this paper I will briefly discuss the more sensitive searches that have been carried out and some of the other searches that are arguably quite innovative or have been influential in some other manner. 
Stuart Bowyer (Space Sciences Laboratory, University of California,   Berkeley)
astro-ph.IM