The Man From Planet X is a 1951 Edgar Ulmer science fiction film. Robert Clarke (The Astounding She-Monster, The Hideous Sun Demon) stars. William Schallert (who has an original series Star Trek connection as well as a DS9 appearance) plays a creepy bad guy. Most of the story is told in a flashback from the point of view of Clarke's character, a reporter: "It began prosaically enough..." It's an interesting film.
veoh has the film online, but you have to download their player to watch it. Not a worthwhile endeavor, in my experience, having had trouble with their player in the past.
Moria gives it 3 stars and calls it "a minor entry and not unworthwhile". 1000 Misspent Hours says it's "an unexpectedly good film". DVDTalk calls it "A tiny movie of giant merit" and "a stylist's delight".