i used to play this as a hard hand hitting game.. few kids standing in circle each with their palms facing the air, one palm below their neighbors to the left(or right) and the other palm above their neighbors palm to the right (or left) so that everyone has an available hand to hit the persons hand next to them.. and u chant while hitting (starting soft) saying :

down by the river hanky panky
where the bullfrogs jump from bank to bank
hip hop don't stop listen to the water POP!

and the POP! signifies the hard hitting begins.. and it continues until one by one the hitting gets so hard and intense ppl drop out the game until its just two ppl left and then they go at it sometimes yelling (POP!) as they hit each others hands. and then who ever quits, their opponent is the POP! champ. I was the POP! champ all throughout 5th and 6th grade (its a horribly painful game, leaving children with itchy red palms.. but it helped prove alot for me.. it made me tough lolol)