Mary-Kate Olsen ...Mary-Kate Olsen, left, and her twin sister Ashley are actually fraternal twins. (AP Photo/CP, Derek Oliver)
Scarlett Johanss...Scarlett Johannson has a twin brother named Hunter. (AP Photo/Stephan Savoia)
Gisele BundchenThere are two of these gorgeous gals - supermodel Gisele has a twin sister. (AP Photo/Miguel Villagran)
Ashton KutcherAshton Kutcher has a twin brother named Michael. (AP Photo/Kirsty Wigglesworth)
Vin DieselVin Diesel (real name Mark Vincent) has a twin brother named Paul. (Photo by Frazer Harrison/Getty Images for First Look Studios)
Joel Madden and ...Joel, left, and Benji Madden are twins and members of the rock group Good Charlotte. (AP Photo/Matt Sayles)
Cole Sprouse and...Identical twins Cole Sprouse and Dylan Sprouse star on 'The Suite Life of Zack and Cody' on the Disney Channel. (Photo by Frazer Harrison/Getty Images)
Alanis Morissett...Alanis Morissette has a twin brother named Wade. (AP Photo/Reed Saxon)
Tamera Mowry and...These twin sisters starred together in the sitcom 'Sister, Sister'. (Photo by Frazer Harrison/Getty Images)
Elvis PresleyElvis had a twin brother named Jesse who was stillborn. (Photo by Liaison/Getty)