From the I-miss-Mr-Wizard Department: This actually sounds like a lot of fun:

Hey kids! Try this at home. Pour clean water onto a small plate. Wait for all the ripples to stop. Then mix a small amount of mineral oil with an even smaller amount of detergent. Squeeze a tiny drop of that mixture onto the water and watch in amazement as the oil appears to pump like a beating heart.

Even better, the explanation involves the word "flummoxed", which gets short shrift in science writing these days. :-)