My very first childhood camera was a Keystone 125X, a little plastic brick that took 126 film cartridges, and served me well on class trips to the Museum of Natural History. When it came time to upgrade, I saved up for a Kodak Pocket 110. Slim profile, sliding lens cap, thumb-operated film advance lever; at about an inch thick, I could actually slip it into a pocket. This was the camera for me.