Tales of the wastes

 refers to an unmarked quest in Fallout 3.

Talk to Knock Knock in Little Lamplight. If the Lone Wanderer asks her for a joke and laughs at it or pretends they found it funny, she will ask the Lone Wanderer for tales from the Wasteland.

This quest has basically 3 stages depending on progress in the main story. No matter where the Lone Wanderer is in the main quest, she can be told the first stage, about exiting the vault. After completing The Waters of Life, the Lone Wanderer relays James's sacrifice. The final part of the story details the escape from the Enclave in The American Dream.

Reward

 * Recognition, acclaim or infamy among Little Lamplighters