Check out the Ghost in the Shell: Stand Alone Complex episode Automated Capitalism - ??$. The assassin has a cybernetic arm concealing a shotgun that fires currency. It owns.
I remember hearing hints of a bottlecap shotgun shell.
Don't let the e-thugs get started now. "I put a cap (or dozen) in yo' ass!"
Anyways, I find it funny that people say a poker chip won't do much damage in Fallout: New Vegas. I remember blowing a Mirelurk's face up with a teddy bear in Fallout 3.