We have done tons of different versions of coke relays, but this is definitely the one that has stuck out as the best. This youth group relay is extremely messy but something the youth will definitely remember.
Give each group a 6 pack or 12 pack of coke and a pen. Have a pitcher or glass on one end of the room (or parking lot) and have the youth stand on the other end. The youth must shake the can, stab it with a pen, and squirt the coke in to the mouth of another youth. Using only their mouth, each youth must take as much coke over to the other end and spit it in to the pitcher. Only allow one youth to run at a time.
The winning team will be either the first to fill the glass or the one with the most coke in their pitchers after a set amount of time.
There is obviously a slight danger because of the stabbing with the pen, so watch the age and maturity of the youth you let handle the pen.