Set up a play area into 3 sections. Two parallel lines approximately 20 feet apart. Everyone in the middle, in the area between the two lines. Two other people (1 on each side of the other lines) begin rolling the inner tube back and forth to one another, through the middle area. As each child is hit by the inner tube, they are not out of the game, they simply join the other team in rolling the inner tube to tag the others.
The faster the inner tube is rolled back and forth, the more fun we have.