As phones continue to get larger, some wish for full functionality in a small package. Oppo's new "slide-phone" concept is meant to deliver exactly that. Designed in collaboration with Nendo, it has three foldable screens attached by hinges, letting it fold up to a more pocket-friendly size. As such, users can expose as much or as little of the screen as needed, while a pop-out stylus offers expanded productivity. No word on if a production model is being considered.