Physicists studying the motion of sperm have found that the little swimmers flock together in tight groups if the surrounding fluid is "viscoelastic".

Homemade spaghetti noodles exhibit a roughened surface that’s the result of viscoelastic behavior known as the sharkskin instability. 

When most people think of foam mattresses they are thinking of memory foam or viscoelastic foam that molds to the contour of your body.