The powered exoskeleton has been a go-to special effect in science-fiction films from Aliens to Avatar. And it's one area of technology where the science and the fiction aren't too far apart. Several exoskeleton systems are already in use or in active development in the U.S., Europe, and Asia. Many are designed for medical use aiding the disabled, and some have emergency response or military applications. Several companies, including Panasonic, have consumer exoskeleton models in the works, and the robotics company Cyberdyne -- that's right, Cyberdyne -- recently started hospital trials of its HAL 5 full-body exoskeleton.