Make the participants divide themselves into two equal-sized rows, or more if you have a lot of participants. Each row has to sit down and hold hands. At the end of each row, there is one plastic bottle. At the beginning of the row, there is a person who flips the coin. The coin needs to be flipped in a way that first people from both rows see it at the same time.
Whenever the coin shows the number side the first person has to squeeze the hand of the person next to him/her. That squeezing motion needs to move to the end of the line as fast as possible. When the last person in the row feels the squeeze he/she needs to grab the bottle as fast as possible.
Whoever gets the bottle first goes to the beginning of their line and the same thing is repeated. The winning team is the row where everybody has been able to grab the bottle or with the most number of wins. No talking is allowed which would give hints that the squeeze is coming.