This is a good conditioning drill and helps players work on making good turns when taking extra bases.
Split your team into 2 equal squads. Have half the team at home and half at second.
Have the first player in line start with the ball in his hand.
On your signal each team will start running around the bases. After each player runs around the bases, he will hand the ball to the next player. First team to get all players completely around wins.
To add a level of difficulty and decision making, use tennis balls and let the players throw the ball to the next player anytime after he has rounded the last base.