Continuity mistake: When Dr. Coleman wakes up in Anna's body, as Lindsey Lohan exits her room her bedroom door is still removed, but a few seconds after she runs out of the room after Harry the door has been re-attached.
Continuity mistake: Right after Anna and Tess leave House of Chang, Tess' organizer goes off reminding her about a parent/teacher meeting. "Tess" freaks out, and "Anna" puts her hands on "Tess'" face to calm her down. The organizer has disappeared.
Continuity mistake: When Anna and her Mom are first together in their switched states: "Anna" is trying to wake up "Mom" and on the wall, left to the bed, we see this ugly turtle wall ornament. In all shots subsequent, however, it's disappeared.