Continuity mistake: For season 7, episode 5. In the beginning, Piper is wearing a top with the blue skinny strap on her right. For the rest of the episode, you can see the strap on her left.
Continuity mistake: In the beginning when you see Piper and Paige sitting in the car talking on their cell phones, Paige has hers in her right hand. You can see she has a ring on one of her fingers. In different shots the ring is gone. (00:00:30)
Visible crew/equipment: After Leslie decides not to ring the manor's doorbell he turns around, and when he sees Phoebe as she walks up the steps, the reflection of crew members is visible on the car window behind Phoebe. Then as Phoebe and Les are talking, we also see the reflection of the boom mic on the window of the car in the driveway. (00:40:15)
Visible crew/equipment: After Phoebe fails to convince herself to push the elevator button she bumps into Les anyway, and when Phoebe tells him she's a "busy little bee" the camera angle changes, and we can see the pink and white T-marks on the floor. (00:10:00)
Answer: "Hush, Hush, Hush" Paula Cole.