In Morocco, there are spiders that know how to do cartwheels. They can cartwheel down sand dunes, and also up sand dunes, which is more than a little bit remarkable. The scientist who found them, Ingo Rechenberg (a professor at the Technical University of Berlin), does what you do when you find an animal with a unique and ingenious mode of locomotion: you make a robot that does the same sort of thing.
There isn't a lot of information on the robots themselves, except that one of them is named Tabbot, which comes from tabacha, the word for spider in the language spoken by the local Berbers. Rechenberg suggests that the robot "may be employed in agriculture, on the ocean floor, or even on Mars."
Robots that roll and tumble definitely have a lot of potential when it comes to negotiating rough terrain, like sand, rocks, or even wet and slippery surfaces. These robots use large portions of their bodies to come into direct contact with the ground, which often allows for better weight distribution and traction than legs or wheels. It's sort of like having tank treads or other high-traction mobility system, except that by rolling, the robot can be significantly more energy efficient.
Whether or not these robots end up doing anything practical, we always love to see creative bioinspired designs that actually work like the animals that they're based on.