A knack for inventing simple solutions to everyday problems -- and marketing them on cable TV -- catapulted Joy Mangano to business stardom. Her first hit was the self-wringing Miracle Mop; she sold 18,000 in 20 minutes on QVC in 1992. Then came no-slip Huggable Hangers and the roll-up storage system RolyKit. She sold her company to USA Networks, but remains its president and a regular on the Home Shopping Network, racking up sales of $100 million a year. -- by Abha Bhattarai