If you have a place in your house where the lighting is particularly bad, sticking a little LED light on the underside of a cabinet or on a wall is a great solution. If you want a little more control over the light, Hackaday community member Thomas Snow added in motion control.
Snow uses an ATTiny85, a string of LEDs, and a few other smaller parts. With the setup now, you can wave your hand to turn on the light, then adjust the brightness by moving your hand up and down. It's a fun and clever solution, and doesn't take a lot of electronics knowledge to replicate yourself.
Motion Controlled Cabinet Light [Hackaday]