Release a tall stick and a short stick and let them fall and note that the short one wins.
Next place a clamp at the top of a meterstick and try to balance it. Then move the clamp lower and lower and repeat, noting how difficulty changes.
Get a hoop, disk and sphere and roll them down an incline to see which wins.
Have races between bottles of water, half full, just a little, totally full, and empty, full and half full of something solid (sand) or thick liquid.

Turning World Inside Out pg 53:
Build a wheel & axle and roll it down a track. Notice that the acceleration is small. The initial potential energy is converted to translational and rotational kinetic energy.
Use rotational motion device and let them change their own rotational inertia.
Use the bicycle wheel to demonstrate conservation of angular momentum.
Tape coins or masses inside cans and have races?

Turning World Inside Out
1) pg 82: F-15 Support one end of a meterstick on the edge of a desk. Line up about twenty pennies on the meterstick and place a quarter on the 662/3cm mark. Suddenly let the other end go. The pennies on the last third of the stick lose contact because this part of the stick has a downward acceleration greater than g. This is Newton's second law for rotation.
2) pg 84: F17 A ping-pong ball rolling in a groove on a balanced beam exhibits oscillatory motion only for precisely determined initial conditions.

Our Stuff:

Roll two hoops of different diameters down a ramp.
Then roll two disks of different diameters down a ramp.
Discuss these two, then discuss with the third graders, the can of chili and can of chicken broth and have them guess which will win a race.
Then have races with a ball and talk about this too.
Let them ride the rotation platform while holding a 1 kg mass in each hand, and bring their hands in to their chest.
Play around with the bicycle wheel