I usually go to the till near the ride on thomas the tank so DD can play on it while I pack and pay. Only yesterday she biffed another child who was playing on 'her' thomas, so I had to go and intervene while the checkout chick huffily packed all 40 or so items into a single carrier bag which promptly broke when I lifted it. Aaaargh! So take away the first and last letter of 'every little helps' and what do you get?
Seriously though, a sweet free aisle with some toys stuck to the wall like at Mothercare would be great, and it would also be lovely if they packed bags without first asking and then glaring at you and then sighing deeply. In Australia they pack bags for you too - and very nicely - heavy things at the bottom and all that.