Using an Arduino or compatible to control a camera for the purposes of time lapse photography isn't that new, however combined with other hardware all sorts of options can be created. One interesting example is a time lapse camera dolly - whic is a small robotic wheeled device that can not only control camera exposures over time, but also move itself between shots.
This has been documented by Instructables member Inevitablecraftslab who has created a small dolly which is propelled via a continuous rotation servo. This allows for easy control by the Arduino and some interesting effects, such as time lapse photography of a flower opening, and chaning the angle of the exposure after each movement.
If you're looking into starting with Arduino and motor control, such as controlling a DC motor (or stepper motor) from your Arduino or compatible, check out our HBRIDGE: DC/stepper motor shield. Based around the powerful Allegro A4954 H-bridge driver IC you can control two DC motors with complete ease, or one bipolar stepper motor. With connections for external power management, a complete beginners' guide and documentation - motor control couldn't be any easier. For more information and to order, visit the HBRIDGE: page.