SETI -- the search for extra-terrestrial intelligence -- is undergoing something of a renaissance, and alongside the work of the scientists almost a million PC users round the world are participating in the SERENDIP IV project through the "SETI at Home" initiative from Berkeley University in California. This book is an up-to-date review of todays scientific thinking about where and how we might find life elsewhere in the universe, presented in Stuart Clarks easily read yet authoritative style.