You can tell us to grow up, but we still love a printed photo in adulthood as much as we did when we were teenagers. And yes, still for the same reason: to display them on our walls.
HP has just released a gadget that was literally made for us nostalgic hard-copy lovers. The HP Sprocket Printer is a Bluetooth printer that prints photos from your phone through their app (available for iOS or Android). It's very similar to Fujifilm's Instax Printer, except it's smaller (pocket-size), the prints has sticky backs, and perhaps most importantly, the film is cheaper. A 20 pack of Fujifilm Instax film goes for $29 (at JB Hi-Fi), while a 20 pack of HP Sprocket film is just $20.
Scroll for a closer look at the features of the HP Sprocket.