In a new stadium in my city you swipe your credit card, pick up food or drink in a little monitored area and walk out with your items. It is an interesting idea but it is also creepy. That's probably what stores will be like eventually -- at least the ones with the resources to implement something that expensive and complex.

As far as self checkout, I don't mind it for small orders or when it is more convenient for me at the grocery store. Unexpected item in bagging is a bad consumer experience, and buying produce/alcohol is also a pain. If I feel like I am going to run into trouble I head for the traditional lines.

I really despise the ones at big box hardware stores that show a video of you checking out. I'm not stealing, don't judge me or make me judge myself with that unflattering angle.