evolve9 presentation at the PTR conference: players are divided into teams. They are sent out to play singles. First to 4 points wins. Players alternate serving but do not switch ends. Winner comes off the court and collects a ticket. Non-winner stays on court and waits for another opponent. The kicker here is that the non-winner retains any points he/she accumulated in the previous match, even though he/she did not win. So when the next opponent comes out, they may have to start at a disadvantage. The idea is to handicap the lower level players a little bit so that presumably at some point they, too, will come up with a win.
Being on court with lots of tremendously gifted tennis players that night, I could easily see how this might not be the case for some players and they might get frustrated. But this probably would not occur at a tennis carnival or other event where many beginners will be involved.
We had a very large group, but this would also work nicely for a quick warm-up with a smaller group of kids. Squeeze down to one court of singles with extra players waiting at the net post. This will also get your players used to being observed and cheered during play.