Fallout: New Vegas Glitches

Free Caps (pre-patch)
If you go to Primm and complete the quest "My Kind of Town" and wait three days, the Vikki and Vance Casino should be up and running. Go to the cashier and buy some chips. Then sell the chips back to her. She gives you the money but doesn't take the chips. You can keep doing this for as long as you want. It helps to buy more chips from her to speed up the process.

Note: This only works if you have not installed a patch. I am pretty sure that adding the expansion packs will also make this not work.