Israel unveils portable hunter-killer robot Thu Mar 8, 10:26 AM ET An Israeli defense firm on Thursday unveiled a portable robot billed as being capable of entering most combat zones alone and engaging enemies with an onboard armory that includes a machine-pistol and grenades. The VIPeR, roughly the size of a small television, was invented as part of Israel's efforts to develop weaponry that could reduce the risks to its forces from hand-to-hand fighting against Palestinian or Lebanese Hezbollah guerrillas. The manufacturer, Elbit Systems Ltd., said that the VIPeR's small size and dual treads enable it to move "undeterred by...