A friend of mine showed me the balls she had made out of some seat cushions from an old couch. The balls were great, but taking scissors to my own couch cushions seemed like a really bad idea. Instead, I found some foam carpet padding that has a thin plastic coating on one side. This stuff is perfect for making these soft, safe balls, and if your local carpet store is generous with their scraps, it will cost you nothing.
Games to Play:
Sea Urchin Soccer
Use 2 chairs as goalposts and play as you would the real game. If you're really good, you can play "sit-down soccer," in which you shoot the ball with your hands but your bottom must stay on the ground.
Up in the Air
Sea Urchin Balls are great for practicing the techniques used in Hacky Sack. The foam balls travel slowly and don't hurt you if you get beaned. Practice with 2 or more people, kicking the ball from one player to the next without letting it hit the ground.
This is a simple one: the person who is "It" throws the Sea Urchin Ball at the other players. If he hits someone, that person is the next It.
Set up an empty box or recycling bin and try to shoot the Sea Urchin Ball into it. A basket from 10 feet away gets you 1 point; from more than 15 feet away, you get 2 points. The first player to get to 21 points wins.
To make your ball more colorful, draw some squiggly lines on the coated side of the foam and let the marker dry.
Use scissors to cut the foam into 24 strips, each a foot long by a half inch wide, then cut each strip in half to make forty-eight 6-inch strips.
Stack all the strips together and hold them tightly while another person wraps a nylon cable tie around the center of the stack.