Forget Jennifer Aniston, the most popular celebrity hair these days is on Jessica Simpson's head. But Jessica's longest locks aren't entirely her own. Like many celebrities -- Paris Hilton and Nichole Ritchie included --Jessica has human hair extensions that she and her best friend and hairstylist, Ken Paves designed and created Find out how these extensions work here. Photo right: Courtesy of www.hairuwear.com. Check out their Website, full of pictures.