Question: Got a good one for you: I remember a movie from a while back about a baby-sitter. The phone rings and the caller is in the house; she's also getting calls at, I think, her dorm room or apartment. This movie was so scary but I can't remember what it was!
Answer: I'd say it was probably When a Stranger Calls (1979), with Carol Kane as Jill Johnson, a teenaged baby-sitter who keeps getting calls asking whether she's "checked on the children." The first 20 minutes is a truly scary retelling of the classic campfire story, but it drags seriously in the middle, when the focus shifts to the psycho killer. It picks up again years later when he places a new phone call to Jill, who's having dinner with her husband at a fancy restaurant, to ask if she's checked on her children. But no one even remembers that there is a middle because the beginning is so suspenseful. When a Stranger Calls is in the process of being remade by Simon West, with Camilla Belle stepping into Kane's shoes.