Ashley Olsen (L) and Mary-Kate Olsen arrive at the Museum of Modern Art in New York, November 17, 2009. The twins have a clothing line and now their own couture label.
Musician Justin Timberlake watches the rehearsal for his William Rast collection show at New York Fashion Week, February 16, 2009.
Designer and musician Gwen Stefani during a presentation of her L.A.M.B. Spring 2010 collection during New York Fashion Week, September 10, 2009.
Kate Moss models her Kate Moss clothing range collection in the window of the Top Shop in central London, April 30, 2007.
Beyonce performs during a concert at Olympic stadium in Athens, November 8, 2009. Beyonce launched the "House of Dereon" fashion line in 2005.
Nicole Richie at the 13th annual Race to Erase MS in Century City, California, April 13, 2007. In October 2008 she debuted her "House of Harlow" jewelry line and recently teamed up with A Pea in the Pod to create a maternity collection.
Hip hop artist Jay-Z performs in Berlin, November 5, 2009. Jay-Z launched the "Rocawear" lifestyle line in 1995.
Sean "Diddy" Combs during New York Fashion Week, September 11, 2007. Combs launched the "Sean John" clothing line in 1998.
A model shows swimwear from the collection of Jessica Simpson during Mercedes-Benz Fashion Week show in Miami Beach, July 14, 2007.
Singer and actress Jennifer Lopez talks to the audience before presenting her Sweetface Fall 2006 show at New York Fashion Week, February 10, 2006.
