i used to work ones at supermarket..giving me free access for scanners,
reading barcodes essays [orc's old one] really got me interested..
understanding barcode's ean-13 check sum is nothing to be facinated from, but when u come with a piece of plain paper where u print at home [using ur own program/freeware] to the super and scan it [gun scanner] and actually works, u get a green lightbolt above ur head =)
although i was only testing the scannners, i didn't went trew the actuall buying system, but this is a good way to buy higher items at lower prices..
i am pretty sure they wont notice u put other barcodes on the item =)
- Ben -