Twice now I have used my credit card at the Big C supermarket where it has been swiped and I have not been asked to confirm PIN or sign the transaction slip. I have no idea why this has occurred, simply that it has, but it does make me wonder if the cashier will accept my card from wifey and notices it is titled "Mr" on the card, whereas she obviously isn't.
We must try this out sometime as it always bugs me how Americans seem to toss their plastic about inviting others to add whatever to their bill. Don't they have any security in the States when using credit/debit cards? Can anyone use someone else's card?