Here are some interesting links:
Adafruit: 'NeoPixel Uberguide'
The "NeoPixel" string of LEDs are super, in that they are individually programmable. A bit pricer, however. Each LED is individually addressable by a computer signal, enabling each LED to have its own intensity in Red, Green or Blue (RGB). These can be programmed by Arduinos, among other platforms.
SuperNight LED strip on Amazon
These SuperNight LED strips are cheaper, but, from what I can tell, can only be programmed by the whole string being one color and one color only. You can make the color different, but it is still one color for all lights on the string at any one time. And I don't know how to use an Arduino to program it.
Multiple vendors sell these strings. To get them working, you'll need to read the directions pretty carefully. I had to do a bit of soldering and a little Arduino programming. Once I got all the parts in place, it took me about a day to get everything running properly.