Supermarket self-checkouts. Good, bad, indifferent, nightmare ?

Useful if you have bar codes, but can be a hassle for items that don't have them and aren't easily found in the store lookup. I use them when buying a small number of items with bar codes.
The,self checkout also doesn't let you select a number of the same item and scan once, it makes you scan each item individually aand place it in the holding area, reminding you to leave scanned items in the holding are rather than scan one item several times.