There are a couple of people on the board that do use a lightwedge. I personally use what I think is called the relight. Its a rechargable booklight, but I don't really recommend it. I have two of them, but I have a constant issue with it dimming and flickering. The light also keeps on falling towards the screen, too. I got it as a gift, but I still use it.
Edit: Found it

ReLight Rechargeable Book Light
Edit: Found it

ReLight Rechargeable Book Light