I have never had it take less time to swipe a card, wait for a fucking receipt for a soda that I'm clearly not going to return, and sign it (or swipe, enter my PIN, say no to cash back, confirm again that I agree to pay $2 and then wait for the pointless receipt) than it does to hand someone a five and have them hand me three ones.

Edit: I will say, I pay for almost everything with my debit card and it's certainly my preference. I just think it's silly when people act like it's completely unreasonable that they still have to fork over some cash from time to time. I'd rather carry a bit of cash on me than to pay a $.50+ transaction fee on a small purchase, pay an extra ten cents per gallon when I fill up, or pay at the expense of a small business with high transaction fees. Not having cash is not going to stop me from making a small purchase, but it is my preference to help support business who provide a product/service I love by helping them avoid unnecessary costs whenever possible.