NEW YORK (Fortune Small Business) - When sculptor Richard X. Zawitz, 58, invented the Tangle Toy in 1981, his decision to create a business out of a twistable cable of interlocking plastic pieces seemed not the least bit wise.

The product was inspired by the Tibetan infinite knot, a Buddhist symbol of wisdom. But Zawitz insisted on its many uses: as a toy, a stress reliever, a creative muse, even a catalyst for world peace.

TWIST ENDING: In late 2003, Zawitz spotted some Wal-Mart executives at a trade show and insisted that they give his toy a twist. Within six months his colorful knots were flying off Wal-Mart shelves.

Other retailers such as Target and Walgreen soon came calling. So far this year more than 3.5 million Tangle Toys have been sold.