(written from a Production point of view)
Tinsley Transfers is a company that provides temporary tattoos, or transfers, for actors and extras on Hollywood films and television series. They created special make-up effects tattoos for cast members on the set of Star Trek: Enterprise and 2009's Star Trek.
Tinsley Transfers was established by make-up and special effects artist Christien Tinsley in 1999. The company was created out of necessity during the film of the 2001 film Pearl Harbor, in which numerous extras required daily application of multiple wound and burn effects. To create these effects, Tinsley used an easily-applied decal transfer, which saved time while maintaining the continuity of the effects. 
One of the innovative techniques developed by Tinsley was the "prosthetic transfer," a time-saving process created for the 2004 film The Passion of the Christ.  Tinsley's work on this film earned him and Star Trek VI: The Undiscovered Country makeup effects technician Keith VanderLaan an Academy Award nomination. In 2008, Tinsley himself received a special Technical Achievement Award from the Academy of Motion Picture Arts & Sciences "for the creation of the transfer techniques for creating and applying 2D and 3D makeup known as 'Tinsley Transfers'". 
Tattoos designed by Tinsley Transfers have been seen on such celebrities and films as Brad Pitt in Ocean's Eleven and Ocean's Twelve, Vin Diesel in xXx, Sean Penn in Mystic River, and Gary Oldman in Harry Potter and the Prisoner of Azkhaban. They also worked on such Star Trek performers as Kirsten Dunst and Tommy "Tiny" Lister, Jr.
Other productions which have utilized the services of Tinsley Transfers include the films Minority Report, Pirates of the Caribbean: The Curse of the Black Pearl, Master and Commander: The Far Side of the World, Walk the Line, The 40-Year-Old Virgin, Memoirs of a Geisha, Serenity, No Country for Old Men, Flags of Our Fathers, Letters from Iwo Jima, I Am Legend, and many others. The company has also worked on television series such as The X-Files, Firefly, CSI: Crime Scene Investigation, 24, Boston Legal, Nip/Tuck, Prison Break, and projects for Spike TV.