Some programs for Arduinos connected to WS2812 SmartLEDs. See http://www.arunet.co.uk/tkboyd/ec/WS2812SmartLEDs.htm for general introcduction.
After you've downloaded, unzipped, when you try to run any of the programs (sketches), the Arduino IDE will moan about it not being in a folder of the same name as the program.... but it will also offer to remedy the situation. This it does very well. Is this is a major hassle to you, see the page cited above for contact details.