Here's one we missed earlier this year but New Scientist's year-end wrap included its April coverage of a novel (and so far useless) method of propulsion the clever folks at German technology company Festo have created. Festo built the SmartBird flapping wing UAV that captured world attention in 2011, but SmartInversion is a bird of a different feather.
The device gets lift from helium-filled panels and it moves itself forward by turning itself inside out. A smartphone has all the computing horsepower needed to control movement within the windless confines of a hangar, but the Festo folks were stumped on practical applications for the somewhat creepy-looking thing. They launched a competition among German engineering students to find a use for it but the competition page has been taken down.