If you've ever gotten snagged against a bicycle parked in a cramped space, chances are it was the handlebars that got you. FlipCrown is designed to keep that from happening, by allowing cyclists to flip their bars sideways when they park their bike.
FlipCrown currently only works on bikes with quill-style threaded headsets, although a version for non-threaded headsets is in the works.
Users start by installing the device in place of their existing headset locknut, which should reportedly only take about 15 minutes. From there, every time they want to turn their handlebars parallel to the front wheel, they use an included hex wrench to loosen off their stem bolt, then push the FlipCrown's release button and turn their bars 90 degrees. The process is reversed to get the bars straight again.
According to its two Belgium-based designers, FlipCrown is safe (i.e: the bars shouldn't spontaneously flip while the bike is in use) and doesn't affect steering.
In order to slim down parked bikes' profiles even more, they're also offering sets of quick-release pedals. For that matter, they're also offering 15 retro-styled "SlimBikes" made by Belgium's Achielle Bicycles, with FlipCrowns and quick-release pedals pre-installed.
If it's just the FlipCrown that you're interested in, though, that can be preordered through their Indiegogo campaign for a pledge of US$25. A combo pack of FlipCrown and pedals can be had for $55. Delivery is scheduled for July, assuming all goes according to plans.