Rolling, Rolling, Rolling
Rotundus, a Swedish company, makes these ball shaped robots that moves by shifting their weight. Neat video of one rolling around a meadow, up and down the (admittedly gentle) contours of the land. The balls can be loaded with various sensors, but the company is one with a product in search of a market. The system of movement reminds me of the Martian "bouncer" Willis in Heinlein's The Red Planet.