Finger (Fallout 3)

A finger is a miscellaneous item $$

Locations
Once the Lone Wanderer gets the Lawbringer perk they are found on evil characters (such as Raiders, slavers, Smugglers, Enclave soldiers, and Talon Company mercs). They have no weight, and while they have a value of 1, Sonora Cruz of the Regulators will reward the Lone Wanderer with 5 to 10 Caps and +10 Karma for each finger.

Bugs
Sonora Cruz can't take more than 999 fingers at a time. If you have more than that in your inventory when delivering, she only takes 999 but still rewards you for all of the fingers (12,800 Caps for 1,280 fingers with very good Karma, for instance). You can deliver the remaining fingers for more Karma and caps.