It's certainly not uncommon for people to ride their bike to the market, then use a shopping cart to gather their groceries, and then transfer those groceries back to their bike for the trip home. The Tricksy is designed to simplify matters, by serving as both a trike and a cart.
Created by Swedish designer Göran Durgé, the Tricksy is pedaled like a regular upright tricycle while en route to the store. Upon getting there, though, the rider lowers its seat, then simultaneously pulls its cargo basket and front wheels back into the folding frame.
Doing so makes the vehicle both shorter and narrower, so that it can easily be wheeled around indoors. In "cart" mode, the single rear wheel becomes the front wheel, as the rider utilizes the existing handlebars to push the Tricksy from what was previously its front end. Once it's time to pedal home, the conversion process is simply reversed.
Durgé is now finalizing the design, with an eye towards taking the trike into production. He is aiming at a complete weight of under 20 kg (44 lb), with possible added features including a lockable weatherproof cargo basket that can be interchanged with modules such as a child seat or heated food-delivery box, along with an electric-assist motor.
To that end, he has turned to Kickstarter for funding. Various pledge levels are available, with the estimated retail price sitting at approximately US$2,500 (assuming it reaches production). You can see the Tricksy in action, in the video below.
Potential backers might also want to check out the Salamander, which is a bicycle that can be converted into a three-wheeled stroller.
Sources: Kickstarter, Tricksy