To create a real cheap and simple but efficient swing:
- just get a pool foam noodle (with a hollow core) at Wal-Mart, K-Mart or some super market,
- a piece of 3/4" poly rope from Home Depot or so
- a place to tie the rope to
- string the rope through the noodle,
- attach the rope ends,
- sit on the noodle and
- swing!