This book introduces the importance of mobile ad-hoc networks in our everyday life, and examines some of the core issues associated with this technology, such as routing, network performance, battery life, and security. It then introduces mobile software agents, as a revolutionary approach to countermeasure those issues, by taking advantage of their inherent characteristics, such as autonomy, mobility, communication, and adaptation on dynamic environments. The book defines a novel agent-based routing protocol that can increase network performance and scalability, provide Quality of Service and energy conservation of handheld devices, and allow the network to automatically reconfigure itself according to its needs. Applications can be found in disaster relief scenarios, health care systems, personal area networks, military, and so on. Perhaps, the most interesting application of the future is medical nano-agents. These agents could be injected in a human body, and act as a group of sophisticated surgeons that can operate at a nano-scale, or as a group of medical guards that constantly protect the body from viruses, and other illnesses.