This is a great [tag]baseball training drill[/tag] to build hand-eye coordination, quick reaction and to teach older players the value of knocking the ball down at all costs. 
What you need (set up): Have one or two groups set up with 5 or 7 players in a line facing the [tag]coach[/tag]. Gloves on and players are spread out about 10 to 15 feet apart. One player should be snagging balls for the coach.
How this drill works: The coach will be about 15 feet away from the player and will begin to hit grounders and line drives to the players. He or she does this in random order – the players do not know where the ball is going to be hit. They need to react quickly and then throw the ball to the player fielding balls for the coach. The coach will hit the ball as quickly as he or she can to the different players. Players are eliminated from pepper for missing balls or making errant throws.
The players must also communicate with one another so there is no problem with collisions on the field. This happens in [tag]baseball[/tag] and can be eliminated if players talk to each other while on the field.
The focus should be on: reading, reacting, and making a good throw to person collecting balls for the coach.
Results: Your players will improve their coordination, reaction to the ball and working under pressure to make a good play. Not to mention the improvement on the reaction time to get to the ball. This is a good drill to round out the fielding skills of your players.