As a rule, serious 3D printers need equally serious design skills if you're building objects from scratch. That's no longer true for MakerBot's Replicators, though; the company has just trotted out PrintShop, an iPad app that takes the hard work out of making simple objects. You can build your own bracelets, rings and signs without knowing a lick about modelling software. If you'd like to craft something a little more sophisticated, you can browse a collection of ready-made items from the Thingiverse. We'd still suggest a rookie-friendly device like Printeer if you're primarily interested in basic designs, but this could be an easy way to let your kids in on the action -- or just to make something without leaving your sofa.