Bounty

In Fallout 3 you can collect bounties from good or evil characters. Before that, you must have related perk - Lawbringer for hunting evil or Contract Killer for those with absence of moral fortitude.

Lawbringer
With this perk, every (human) evil character drops finger, which can be sold to Sonora Cruz at Regulator HQ for 10 caps and Karma increase. Besides, there are certain characters, whose price is bigger:


 * Junder Plunkett finger can be traded for 1000 caps.

Contract Killer
With this perk, every (human) good character drops ear, which can be sold to Daniel Littlehorn at Scrapyard for caps and Karma decrease.