Infinite Caps From Slavers
In the quest "Strictly Business," one of the people you must enslave is Susan Lancaster. After putting a slave collar on her, get your payment from Grouse back at Paradise Falls. After receiving your payment, go to the slave quarters in Paradise Falls and talk to Susan (you'll need a key to open the gate to the slave pen, so pickpocket one). Talk to Susan and when she asks for help, choose the option "You're a slave. Deal with it.", then return to Grouse to collect the reward again. Grouse will think that you captured her again. You can repeat this as many times as desired to get 250 Caps and a slave collar each time.
Note: There is a downside to this trick. Each time you talk to Grouse to receive payment, you also receive a slave collar. These collars each have a weight of 1 and they are listed as quest items, so you can't drop them to lose weight.
Added by: TheEvilSpartan117 Jun 30th 2009, ID#4668