The Oskar is solidly built from aluminum plates, with the cord out the back and the on/off switch in the front. Again, perfect for sitting on your book shelf: The cord is hidden in the back, while the switch is easily accessible in the front. It uses a 50W halogen bulb which is a little on the bright side for my tastes, but it gets the job done.
These were initially available from Ikea for about $20 but now it looks like if you want one you will need to consult ebay.
Light Reading Book Lamp by Sam Johnson
The book lamp disguised as a book that will not heat damage its shelf mates.