Retailers, including Wal-Mart, are trying to adapt their models to suit urban areas, including this mixed-use retail and residential development in Washington, D.C. Meredith Rizzo/NPR hide caption

Traffic on Staten Island during a winter storm earlier this month. New York is among the states affected by a shortage of rock salt. Tom Checchi/Staten Island Advance /Landov hide caption

Iranian high school students sit for their university entrance examination in Tehran in 2009. Iran's economy has been struggling in recent years, and many graduates feel they have few career options. Mona Hoobehfekr/AFP/Getty Images hide caption

Porn has a distinct problem that less racy media companies don't have: Users are afraid of leaving a digital record. Paid sites are trying to lure viewers out of the shadows and into credit card payments. iStockphoto hide caption

Pastor Jamie Coots holds a snake at Full Gospel Tabernacle in Jesus Name Church in Middlesboro, Ky., last year. NGO hide caption

Good things come in small packages. Lacy Williams, an architecture student, and her boyfriend, Patrick Beseda, built a WikiHouse to live in during a field project in Utah. Patrick Beseda and Lacy Williams hide caption

Local authorities celebrate a demolition explosion that's part of Rio's Porto Maravilha urbanization project, in Rio de Janeiro, on Nov. 24, 2013. The state- and federal-supported project is part of the city's redevelopment ahead of the 2016 Summer Olympic Games. Pilar Olivares/Reuters /Landov hide caption

Everard Hall estimates he's dug about 2,500 graves over nearly 50 years. Some have been special: "I buried my mother, my father, my grandfather, and two aunts and two uncles. And I buried my sister Marilyn." Jennifer Mitchell/Maine Public Broadcasting Network hide caption

Nazi leader Heinrich Himmler and his daughter Gudrun. Vanessa Lapa, the granddaughter of Holocaust survivors, has made a documentary called The Decent One, based on Himmler's letters to his wife and other personal documents. Realworks hide caption