Doesn’t have anything to do with smartphones directly- they’re one more facet of the increasing use of the internet.
The whole “internet of things” is dependent on being able to uniquely identify “things”, which means that each item will have to be able to have its own address.
Once that’s done, they can communicate amongst themselves, and there are a lot of interesting possibilities.
For example, the coke machine mentioned upthread might actually communicate with the company contracted to keep it full, and notify them of the usage patterns, so that the fill-up guy’s route can be optimized.
Or… an appliance might have some self-diagnostic capabilities built in, and in case of failure, could notify the repair place of the fault, and what kind of fault it is, so they can come prepared with the right parts and knowledge to repair the appliance.
Your house could possibly be networked in such a way that your thermostat, lights, blinds/shades and ceiling fans are all controlled in such a way that you’re kept well-lit and comfortable with a minimum of energy consumption.
I’m personally not convinced that the majority of household items have compelling reasons to be networked; what’s the reason for networking my toaster? I still want hot toast in the morning, regardless of when the most efficient time to make toast is, and it’s not like the toaster is really going to better toast my bread based on some kind of internet bread database and a bread type sensor. I mean, it would be more hands-off and more accurate in an academic sense, but it doesn’t take long to figure out where to set your toaster for 99% of breads you’ll encounter, and most people wouldn’t pay fifty cents more for networking it vs. just adjusting the toaster by hand.
I think what we’ll see first is networked lights, air vents and the like, coupled with sensors. That way, they can selectively heat and cool the house at the right times and places to keep the residents comfortable and not spend energy heating or cooling rooms that people aren’t in, or at times when nobody’s typically home.