One person’s junk is another person’s treasure, and at Nate’s Swap Shop 63rd Street Drive-In Flea Market in Kansas City, Missouri, there’s enough of both to make a pirate jealous.

Leading players have significant financial backing already lined up, often from technology companies and future customers.

Our homes have been multitasking for a while now. They may be where we work, they are certainly where we play, and in today’s ...