Autonomous mobile robots can be used to explore hazardous environments and to reduce the burden on a human controller. Current methods such as simultaneous localization and mapping (SLAM) algorithms are able to automate aspects of navigation, with some success in practical applications. However, there is still much work to be done uniting these methods and making them more efficient for use on mobile robots. This is especially important as these robots are becoming smaller with an emphasis on multiple robot cooperation. This article reviews examples of current autonomous mobile robots as well as the technologies that allow the robots to navigate their environment.