AT&T has signed a two-year exclusive contract for the BlackBerry Torch, adding the device to its roster of smartphones. The Torch, designed by Research In Motion, provides new software, a touch screen, and a slide-out QWERTY keyboard. It will start selling on August 12 for $199.99. AT&T, meanwhile, is preparing to lose its monopoly over Apple’s wildly popular iPhone. Rival Verizon Wireless, according to sources, will begin selling the iPhone when AT&T’s contract runs out in January. The Torch will also be sold at RadioShack, Best Buy, and Wal-Mart stores.