The movement made by standing still and then shifting your weight back and forth ever-so-slightly. This 'dance' is in relation to the film Paranormal Activity in which the time lapse shot of the main female character standing over her partners bed appears to make her 'dance'.
This movement can also be used to freak out your friends in the middle of the night.
Adam: Yeah! Kevin was so drunk last night all he could do was break out into the Paranormal Activity Dance.