Ask HN: How do I launch a ping-pong ball across my office with Arduino?

I (and my coworkers) have started playing around with arduino.

I want too create a sh*y (simplest) racquet made of plastics, 'glue' it to a strong enough electric motor (servo?) and launch the ball across my office.

I have a servo motor in my starter arduino kit and it's not strong enough. People smarter than me suggested a spring of some kind. Is it possible to do this with just an electro-motor (what kind???) ? I'm willing to pay quite above average amount for components to get this to work with an electro-motor.

How would you launch (repeatedly) a ping-pong ball across an office?

edit: I want to swing my 'racquet' to launch the ball if possible.