Supermodel Cindy Crawford has purchased 4811, her publicist confirms. Manhattan boutique La Petite Coquette says actress Julianne Moore bought 4811 "in a rainbow of colors" earlier this year. It's the top-seller in its category at Trousseau in Chicago among working women. "I can't get customers to try anything else," says owner Christy Horton.

For the last decade and a half, a little-known company called Hanky Panky has thrived making a $15 lace thong known simply by its style number, 4811. In the cutthroat world of lingerie sales, that is no small thing.

What gives? Well, the undergarment itself does. "It's really, really soft and super-stretchy, so it doesn't dig into you like all the other brands," Ms. Horton says. "We call it our starter thong."

Thongs are the biggest thing to hit underwear in the last 20 years. They accounted for one-quarter of the entire $2.6 billion panty market last year, according to NPD Group, a marketing information company in Port Washington, N.Y. Once the domain of a daring few, thongs have gone mainstream. You can buy them at Wal-Mart for $1.50.

Hanky Panky has just a tiny share of the thong market. But even among women who favor fancy Italian and French brands -- Cosabella, Argentovivo, Lise Charmel -- the made-in-the-USA 4811 has a cult following.,00.html