The dual-screen Sony Tablet P will launch on the AT&T network on March 4th and bring the network\'s \'4G\' speeds to the device. The unique, clam-shell tablet will cost $399, which isn\'t all that much of a discount, on a two-year contract, with expensive data plans on top of that. Rather than full 4G LTE internet, users will only have access to the still-pretty-rapid HSPA+ download speeds available on the AT&T network. Users will need to pay $35 a month for 3GB of mobile data or $50 a month for 5GB of downloads. PlayStation Certified and more... The Android 3.2 Sony Tablet P launched late last-year with two Nintendo DS-like 5.5-inch screens, allowing users to use one screen as a controller and another as a gaming screen. The PlayStation Certified device, which also brings access to the Android Market, comes loaded with a 1GHz processor, 4GB of internal storage, a VGA webcam and a 5-megapixel rear camera.