Swinging clubbers

The Tiger Company of China has produced a golf club that can display the
trajectory of an imaginary ball. The strength of your swing is sensed by an
electronic pendulum mechanism in the head of the club. A microchip gauges the
speed and direction of an imaginary ball hit by the club, and the supposed
trajectory is displayed on a small screen in the head. The club is meant to be
for fun rather than serious practice, but there may be a lot of demand for it:
golf-mad Tokyo commuters can often be seen swinging away with their
umbrellas.