It's been exactly half a century since space aliens began taking over earthlings' bodies, and through the years Don Siegel's low-budget sci-fi classic has lost none of its visceral or metaphorical power. The notion of six-foot seed-pods producing bland, unthinking replicas of ourselves has remained one of the most enduring images in Hollywood history. Predictably, the 1956 Invasion bred a serviceable 1978 remake directed by Philip Kaufman and a self-absorbed teenager version in 1993, courtesy of Abel Ferrara. As the original's clone-resistant doctor hero, Kevin McCarthy, could tell you, though, there's no substitute for the real thing -- in people or movies. In a mood to renew the old debate over whether director Siegel and novelist Jack Finney were warning us about the incursion of Communism or the paranoia of right-wingers? Have at it, iPodsters.