What's the worst part of going to the grocery store? If you said the checkout line, you'd make a lot of software engineers very happy. This week, Amazon and Walmart both announced their own projects to simplify the grocery shopping experience by using technology to radically cut down on line time.  

Amazon's store uses a system of sensors and cameras to track customers and the items they pick up, no barcode reader necessary - simply walk in, take what you want, and walk out. Your purchases will be charged directly to your card. To use Walmart's system, pick out your items in advance online; they will be bagged up and ready to go when you walk into the store.    

The most interesting part of these pilot programs, though, is what they're not: namely, delivery services. Both still require you to go to a physical store, pick up your groceries and bring them home, which in an era of Uber and Amazon Prime might sound strangely off-message. But it's also a sign that these big retailers know there's still an appeal to shopping in person, and sometimes an online-plus-showrooming one-two punch is the most effective strategy.    

And it's still the fastest way to get what you want when you're planning the dinner menu at the last minute.