http://www.patents.ibm.com/details?&pn=US05443036__
A method for inducing cats to exercise consists of directing a beam
of invisible light produced by a hand-held laser apparatus onto the
floor or wall or other opaque surface in the vicinity of the cat, then
moving the laser so as to cause the bright pattern of light to move in
an irregular way fascinating to cats, and to any other animal with a
chase instinct.
Yes, that's right. If your cat chases a laser pointer under your control,
you owe this putz money.
/cco