What an awesome idea. 2 good 2 lose put solar spot lights in their house to light up stairs, closets and even the kitchen so they could see at night without having to turn lights on all through the house. I love this idea and need to do this with a closet that has no light fixture and on the basement stairs as even in day time it is not really safe to go up and down them without turning on the light. These would be a great thing to have in a power outage as well. Probably not enough to read by but would definitely be better than pitch black.
Outdoor Solar Lights Inside the House
http://2good2lose.com/solar-lights.shtml