There are a number of products available that do similar things, but that's a decent option for third world countries where they have empty bottles and water, but may not have recycling programs and access to the products we have now.
It's all a new take on an old idea anyway. Buildings have been built with light wells for about as long as people have been stacking sticks and stones to make a home.

Yes, CF bulbs save power, and that's great - but manufacturing and disposing of them negates their environmental friendliness... -Q!

so... how do you turn them off?