Raspberry Pi is among the most popular choice for low-cost computing hardware among makers and engineers building prototypes and hobby systems that do virtually anything from run home automation systems to acting as full desktop computers.
For about $35, you can purchase a working computer including: motherboard, processor, RAM, 10/100 ethernet, microUSB power, full HD and audio out, USB ports, and a slot for microSD storage. In fact, the latest generation of these products include on-board wireless N for easy wireless networking