As you get hungry, you look around for a place to eat. You visually pause as you scan the street, and menus pop up with prices, along with the current estimated wait time for a table at the better establishments. "Not bad at all," you think.
You decide to wear these little gadgets on the camping trip with your son's scout troop. You are not much of an outdoorsman, but that's no problem at all. Along the trail you spot an interesting-looking plant, and the "smart bubble" pops up over a leaf, after which you proudly spout off that it is a Toxicodendron rydbergii, better known by its common name -- poison ivy. And just to earn extra points with your son's friends, you casually add, "It was, of course, first described by Captain John Smith in 1609."
This view of the future is not some hypothetical sci-fi cartoon. It (or some beta version) is just around the corner. Complaints have emerged from privacy advocates and others concerned with the intrusion of technology into our lives. These issues will have to be sorted through by tech philosophers and the legal system, but we will get there very shortly, one way or another.
Now, where do I find the X-ray mode on these things? Wow