My apartment has sub-par to poor lighting.  Combine that with our lease’s “no painting walls” policy and you’ve got a one-way ticket to Drab-ville.  Many moons ago I planned to replace the over-cabinet lighting in our kitchen with RGB LEDs controlled by Arduino, but I never found the motivation to actually do it.  Then one day while browsing Adafruit’s website, I found their RF remote and LED controller and I couldn’t not get one.  After a few evenings of tinkering, I decided to forgo the kitchen and install the bright, colorful goodness in my bedroom instead.  Red, yellow, green, blue, light blue, purple, white, and a decent selection of colors in between thanks to the nifty touch wheel remote.  It also features pre-programmed modes for color-changing sequences, fades, and controls for speed and brightness.  Definitely worth the time and effort.