Waitaminute. Are we talking, glue-macaroni-salad-to-their-forhead (aka Star Trek) aliens, or Barlowe's Guide to ET's aliens, or "It came from some, alien, antimatter galaxy at the other end of the universe" aliens, or ALIEN aliens, or boy, that's weird! aliens? Sixus has been making some ver' strange beasties for a while. Various people have taken a whack at creatures from mythology and fantasy. Fae are, of course, ubiquitous (although they sulk from Renderosity of late). So what is an "Alien" to you? BTW -- I always heard it as "The Drake Equation," not "Drake's Equation." Unfortunately the variables grow larger and larger towards the right side of the equation, until you might as well say "I guess so. I dunno." And isn't the Fermi paradox pretty much a reworking of Olber's Paradox -- applying Olber to the concept of intelligent, radio-using species? I rather like the Dyson wrinkle on that anyhow; visible light is evidence of waste, and the fact that we still see stars in the sky is pretty good evidence there isn't a technological civilization of the sort we Western Capitalists would recognize out there.