There are already plenty of products that let cyclists save floor space by parking their bicycles vertically against the wall. Almost all of those systems, however, require users to lift their bikes up so that the front wheel can be placed in a wall receptacle or over a hook. The Lithuanian-designed Parkis makes things easier, by doing the lifting for the rider.
To use Parkis, cyclists just wheel their bike into it front-first. As soon as the front wheel engages the built-in dolly, a spring pulls that dolly vertically up a wall-mounted rail, pulling the bike along with it. All the user has to do is keep their hand on the saddle, to help guide the bicycle as it goes up.
When it's time to retrieve the bike, the user just grabs the saddle and pulls back on it, causing the dolly to slide back down.
Parkis reportedly works with a wide variety of bicycle types and wheel sizes, although mountain bikers should note that the dolly maxes out at a tire width of 2.0 inches. The system is currently the subject of a Kickstarter campaign, where a pledge of €239 (about US$260) will get you one, when and if they reach production. The estimated retail price is €359 ($390).
It can be seen in use, in the following video.