NeoPixels are inexpensive, bright, easy to use, and you can use them to build projects of almost any size. They show up in costumes, sculptures, vehicles, and signs. The saturated colors and frenetic blinking of these lights can be hard to escape at parties and festivals.
Fadecandy is a project that tries to solve this problem, by making LED art both easier to build and more expressive. At the core of the project is the Fadecandy Controller, a tiny board that lets you control up to 512 NeoPixels (as 8 strands of 64) from any computer or embedded Linux board with USB. It includes unique color dithering and interpolation algorithms to get the most out of each pixel.
You'll be doing some programming and some basic electronics assembly. If you aren't familiar with programming or electronics yet, don't worry- there are plenty of tutorials on learn.adafruit.com to help you if you get stuck, and you might even find someone near you who would love to help you get started.