KOSOVSKA MITROVICA, Serbia-Montenegro - Getting a good night's sleep in the Balkans can be rough for peacekeepers bunking in a military camp far from home and family for months at a time. So Danish researchers are testing an unusual solution — MusiCure, a soft pillow that chirps like a bird and is designed to lull soldiers to sleep in Kosovo, Iraq and other hotspots. With built-in speakers, the white pillows release sounds from nature combined with acoustic instruments such as cellos to provide a serenade designed to help stressed-out minds shed unpleasant thoughts. Its designers say that if it works,...