I like having some cash to pay for little things -- as I don't have the patience to read a long statement on check out day with items for $5 or less. Mostly, I carry cash on the off chance a machine is down when I want to buy something. Has only happened once (and at
Disneyland not Disney World) but I was really happy I didn't have to get out of line and find the item again later when the card reader didn't work! I can't remember the last time I saw a restaurant/shop/card that didn't take the card, though. Like a pp said, it's mostly just the vendors who are walking around (like the balloon guy) who don't take cards.