On the other hand, here's a story (WSJ: requires subscription) that shows that cutting-edge technology is not always what it's cracked-up to be:

Kmart Corp. wants to cancel leases on hundreds of its self-checkout machines because the systems cost too much to maintain and increase the risk of theft, the retailer says.

Kmart, of Troy, Mich., said the technology, which allows customers to buy merchandise without the help of an employee, may not have any place in its stores after the troubled retailer emerges from bankruptcy...

The story mentions that the technology in the self-checkout machines Kmart is using requires a lot of maintenance, so this is probably not the best test of where this technology is headed. Home Depot has deployed self-checkout machines. Then again, Home Depot is suffering from poor customer service.

Ultimately, retailers will have to weight the convenience of these machines vs. the impact on customer happines just as they currently weigh the savings in labor costs vs the higher incidents of shoplifting. (The adoption of smart tags will make shoplifting harder and make the adoption of this kind of self-checkout technology easier).