The rhythm ring was a finger based percussion accessory, which straps a little ball bearing filled canister which creates a percussive effect when strumming or using hand drums. Now there is the toe tapper, which is the same idea - a larger little plastic can of ball bearings which clips into the front of your shoe - so you get this percussive accompaniment when you tap your foot. The can has to be larger so you can still hear it at player level (the ring being closer to the ear and therefore no need to be as big!).

The toe tapper is great for individuals or groups (well, groups with one each...), and gives a great percussive sound when tapping that toe.