Although it won't be making any high-resolution images in a hurry, you can make your own home-made printer with some basic woodwork, an old optical drive and parts, an Arduino and some motor control circuitry. This has been demonstrated by Instructables user talesgurjao whose printer uses a large felt tip pen for a print head, and three small DC motors for movement:
The included sketch allows the printing of text that is entered into the serial monitor, however could be modified with a little work for all sorts of effects. Certainly an interesting theoretical read at least, and a fun project if constructed. To learn how to do so, visit hte project page. And for more, we're on twitter and Google+, so follow us for news and product updates as well.
If you're looking into starting with Arduino and motor control for mechatronics, cars, boats and so on - 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.