The Raspberry Pi's extra camera board won't win any photography awards, but if you want to make your own camera entirely from scratch, Adafruit has a kit and guide for doing just that.
You'll need a Raspberry Pi, the Raspberry Pi Camera Board, a touchscreen, a battery pack, and a few other parts. When you're done assembling the camera, it will be a solid little point-and-shoot with built-in Wi-Fi (not to mention an operating system) so all your photos automatically upload to Dropbox. Head over to Adafruit for the full guide to build this for yourself.
DIY WiFi Raspberry Pi Touchscreen Camera [Adafruit]