The Outcast Collection Agent

 refers to an unmarked and repeatable quest in Fallout 3.

You can trade some pieces of power armor, some energy weapons, sensor modules, and scrap metal to Protector Casdin at Fort Independence. In return he will give you your choice of the following, in quantities according to the perceived value of the item:
 * 5.56mm ammunition
 * Frag grenades
 * Rad Away
 * Stimpaks

Once the Lone Wanderer has gained 50 "points" (see table below), they are told that they are considered friendly by the Outcasts. This allows for infiltration of Fort Independence without encountering the hostility of the residents (see Getting In).

Value Table
† Scrap Metal must be traded in groups of two; Alien Power Cells must be traded in groups of twelve.

Bugs

 * There is no option to give Casdin a Tesla Helmet or Firelance.
 * You also cannot give him a Gatling Laser, though this may be due to its classification as a big gun.
 * If you give him the Alien Blaster, kill or pickpocket him, and take it off his corpse, its condition will be restored to 100. If you pickpocket rather than kill him, this can be repeated for numerous rewards and repairs.