I was a fluid mechanics lab instructure while in graduate school in the '70's. The favorite experiment we did was to demonstrate "Non-Newtonian" liquids by mixing cornstarch with water. The mixture has amazing and fun properties. Always a hit with the students. Sadly, we could never explain how it worked other than to say it was "Non-Newtonian".
Science Friday has video both demontrating and explaining it. I especially like the idea about tryingit out on speakers.