Arduino, the rising star :P

Arduino can sense the environment by receiving input from a variety of sensors and can affect its surroundings by controlling lights, motors, and other actuators. The microcontroller on the board is programmed using the Arduino programming language (based on Wiring) and the Arduino development environment (based on Processing). Arduino projects can be stand-alone or they can communicate with software running on a computer (e.g. Flash, Processing, MaxMSP).
The boards can be built by hand or purchased preassembled; the software can be downloaded for free.

check out this link for the basics of an arduino operation!
https://www.youtube.com/watch?v=E6KwXYmMiak

usage requires both hardware and software skills, the hardware, thats the arduino board has variants were as the software is coded mostly using C!
this link is worth a read!
http://en.wikipedia.org/wiki/Arduino