LifeHacker makes a strong recommendation for Mr Beams lights:
"Mr. Beams Motion Sensing LEDs Light Up Any Room or Closet Without Wires, Screws, or Hassle. Seldom do new apartments come with enough lighting built-in. If you need a bit more light in certain corners of your home, the Mr. Beams motion sensing LEDs are a great solution. Mr. Beams is a line of super-convenient wall lights that can light up pretty much any portion of your house..."