Companies are inviting their customers to upload their own designs of toys, apparel, jewelry, and other objects onto their Web sites.

Mass customization. Markets of one. These slogans from the late dot-com years conjure a certain glow. The idea was that the Internet would enable a whole new mode of manufacturing that would include direct input from the end customer. Goods would still get mass-produced, but in the final stage, they’d be tailored to the tastes of individual shoppers. Net-savvy startups that mastered the new co-creation paradigm would devour the Big-and-Clueless.

This was all a pipe dream in the 1990s. Now that manufacturing is borderless, electrons are free, and digital design tools are everywhere, the dream is coming true. Companies are inviting their customers to upload their own designs of toys, apparel, jewelry, and other objects onto their Web sites. The designs are produced to the customers’ specifications, and the finished goods are delivered at prices that often undercut branded mass-producers.

So what did the forecasters get wrong? That bit about the Little devouring the Large. Giant Nike was one of the first to invite consumers onto its site to design their own footwear. Toymaker LEGO hands out design tools so kids both young and old can dream up the toys they would most like to assemble. Here’s a look at some of the companies—large and small—that have handed customers the keys to their design shops.

Cool Things You Can Design Yourself