The "normal" puts the chills in Paranormal Activity. The illusion of amateur camerawork and everyday life can make a moving door or a shadow a lot scarier than an elaborate CGI effect, as TheBlair Witch Project (1999) proved. In what seems a homemade Ghost Hunters episode, yuppie couple Micah (Micah Sloat) and Katie (Katie Featherston) employ a video camera to find out what's been going bump in the night.
By the time they get to "Night #20" things have gotten a little repetitious and predictable, but Oren Peli in his feature debut has a few jolts in store, and the natural performances of the cast and the aura of reality provided by the video format keep the tension high. Peli also has something more than cheap thrills in mind, as the film unobtrusively explores the nature of male/female relationships and of filmmaking itself.
It does much the same job as Lars von Trier's upcoming Antichrist, but spares the gory details.