All players stand or sit in a line and are assigned a number. The coach calls out the number of two players then throws or kicks the ball away from the players. The players try to gain control of the ball and dribble it back to the coach. Make sure to alternated the players so that different ones were playing against each other.
I have also seen a variation of this drill where the players lay face down and have to do 5 push-ups when their number is called, before they can go for the ball.