In the future, a hard drive full of photographs may serve as the digital analog of a pile of old pictures. iStockphoto.com hide caption

itoggle caption iStockphoto.com

A Union Army band marches into the "Crossroads of Destiny" battle at the 150th Gettysburg Anniversary National Civil War Battle Re-enactment, on Thursday. The re-enactment activities officially began Thursday and last through Sunday. Chloe Coleman/NPR hide caption

itoggle caption Chloe Coleman/NPR

Bobbie Hanvey and his son Steafán Hanvey, in Northern Ireland. Courtesy of Peter Muhly hide caption

itoggle caption Courtesy of Peter Muhly