Child at Heart (Fallout 3)

Child at Heart is a perk $$

Effects
The Child at Heart perk greatly improves your interactions with children, some adults and a robot, usually in the form of unique dialogue choices.

Little Lamplight
The Child at Heart perk is particularly useful in Little Lamplight, where a lot of children are present.
 * Mayor MacCready will allow access to the town. This is arguably its biggest plus, since it allows either skipping Rescue from Paradise entirely or completing it later.
 * Mayor MacCready will also give permission for trading Buffout and strange meat for cave fungus.
 * Biwwy will give the Wazer Wifle for free (or "fwee").
 * Eclair will trade (1 cave fungus for around 50 caps).
 * Knick Knack will trade his goods at a discount. He can also assist in The Replicated Man, telling about Pinkerton.
 * Zip can be convinced not to open fire (not that he can, since he is not allowed to have his gun with him in town).
 * Bumble can be convinced to go outside Little Lamplight in the unmarked quest The Kid-Kidnapper where she can be lured and kidnapped by a slaver.

Other areas

 * Maggie in Megaton will tell the combination to Billy Creel's safe.
 * Bryan Wilks, in or near Grayditch, will give the key to his father's weapon and ammo stash.
 * Rachael, Ralph and Flower will allow entrance into the Republic of Dave.
 * James Hargrave in Rivet City can steal ammo.
 * Derek Pacion in Canterbury Commons will tell the weaknesses of the AntAgonizer and the Mechanist during the quest The Superhuman Gambit.
 * Dean Dewey in Roosevelt Academy will ask for a hallpass once he is activated at a terminal. He can be convinced about having forgotten a pass with this perk and prevent his hostility.
 * Penny in Paradise Falls can be convinced to leave Rory McLaren behind during Rescue from Paradise.
 * The Mechanist can be convinced to stop trying to be a hero when reminding him that his actions are putting Derek Pacion in danger.
 * Sapling Yew in Oasis will tell about Harold's fear (fear of fire - burning to death) and will give her charm upon completion of the quest.
 * Machete in Canterbury Commons will acknowledge that she was on her way to Big Town but decided she would rather explore and ended up where she is now.
 * Croatoa in Point Lookout can give the Fertilizer Shovel.
 * Kenny in Point Lookout will allow storing one's gear and sleep in his cave without having to search for and return his Kenny-bear.
 * Midea in The Pitt will disclose Wernher's location during Free Labor.
 * Sally on Mothership Zeta can escort the player to a hidden stash in the Engineering Core through an otherwise impassable forcefield.