Tell your friends you have a magic, magnetic comb.

1. Rip up the paper into tiny pieces.

2. Run the comb through your hair a few times and move it over the small paper fragments.

The paper jumps on to the comb.

3. Comb your hair a few more times to recharge it's "magnetic" ability.

4. Place the ping pong ball on a flat surface and bring the comb close to it.

The ball starts to move towards the comb!

Note:
Your comb itself is not really "magnetic." By running it through your hair, your're causing it to get "charged" up with static electricity. This creates a small amount of magnetic activity.