Danielle's book

 is a unique book in Fallout 3. It can be found on the floor next to a bench at the bottom eastern end of the central area of Foggy Bottom Station. It has no special effects or uses.

Behind the scenes
This item, much like the police impound report in Germantown Police HQ you can find for a "Faye, Danielle", is an easter egg. It was put into the game by two of the writers as a tip of the hat to a friend of theirs, named Danielle, who, while not a video gamer, plays an extraordinary amount of LARP games.