Flying Fingers Yarn Shop's famous Yarn Bus may ferry tight-knit Manhattan fiber fans to the Tarrytown shop, but it's a trip just standing still. The roof sports three colorful yarn balls, each six feet in diameter and made of plastic tubing coated in wooly-looking polypropylene. A pair of six-foot-long needles poke through the yarn, and the body of the bus is printed with one of owner Elise Goldschlag's knitted designs. The result looks almost like a big purple sewing basket with wheels. Built by the same guys who designed the Oscar Mayer Wienermobile, the bus is as much an experience as it is a conveyance. 'One customer in St. Louis told us she saved up her frequent-flyer miles and wanted to use them to come here and ride the Yarn Bus,' Goldschlag says. 'Instead of making her go all the way into Manhattan, we picked her up at the airport.'