If you don know , Arduino is an Open source hardware, based on Atmel processors, very easy to play with. It comes with a bundle of board and Ide, open sourced, for free. As the board is now spreaded all over, you can find lot’s and lot’s of interesting projects and libraries, making easy to develop your own projects, using a plethora of good samples projects.
The official site is arduino.cc
It is also good to know, If you want to start playing with Arduino, there is an emulator available, it is called Emulare. I will write about it later…