The back is an excellent location to get a tattoo, and seeing how it's the largest piece of real estate on the human body, many people choose to get very extensive tattoos on the back.
Many celebrities have tattoo designs on their back, checkout LeBron James who has the phrase "Chosen 1" on his back, rock star Tommy Lee has a tremendous amount of tribal artwork on his back, Jesse James has a 100 dollar bill with flames and David Beckham has several tattoos on his back including a crucifixion scene with the names of his 3 sons.
Checkout some pictures of back tattoos.
Nicole Richie has a cute pair of angel wings tattooed on her back, Megan Fox has a short poem that reads "We will all laugh at the gilded butterflies" on her back, Victoria Beckham has a quote from the Song of Solomon 6:3 "I am my love’s and my love is mine, who browses among the lilies." and rapper 50 Cent has "South Side" and a giant number 50 tattooed on his back.
Other famous people with back tattoos include, Ja Rule with crosses and angel wings, Davey Havok has large angel wings which covers his entire back, Josh Hartnett has a Celtic knot, Brandon Boyd has a pyramid with eye and wings tattooed on his back, basketball player Tim Duncan has a jester tattoo design, NBA player Carlos Boozer has a large archangel on his back, Chester Bennington has two dragons and the name of his band, and David Blaine has the "Christ of Saint John of the Cross" artwork tattooed on his back.