My friend Jeff Wilson alerted me to this awesomely large Lomo-styled photo booth his colleague Matt Frank built for his wedding. The camera-shaped enclosure houses a Mac running PhotoBooth, a monitor for instant feedback, halogen lighting, and a hacked Easy button sending serial commands (via Arduino) to the computer. He has an excellent how-to here on Instructables.
I love how many people use an arduino to drive a basic input device like a button. But, there’s an even easier and cheaper way to do that. Go get yourself any cheap usb joystick or gamepad. Rip the guts out and solder in the leads. Instant X set of buttons as input and they’re really easy to access using any of the myriad of joystick drivers available for all sorts of scripting languages.