It's amazing to me how many people wander around obliviously, technology plugged in to all of their orifices, ignoring the meatspace all around them. Deliberately disregarding all forms of situational awareness seems to be all the rage.
For some, it's their God damned Bluetooth devices. My favorite game is, "Bluetooth or Batshit?" I try to figure out if the person randomly commenting to the air around them is actually crazy, or just babbling at top volume into their earpiece. Now, they are safer for driving, but it's disconcerting to be standing at the deli counter, waiting on a pound of provolone, and listen to the guy behind me try to describe the chancres on his junk, and exactly what it feels like when he pees. Likewise, sitting in traffic and listening to the woman in the car next to me talk about her new boyfriend, "Captain Bendy," and all the unique positions they can try out because "it's shaped like a banana!"
For others it's their iPod or Mp3 player earbuds. I have no idea how people survived without a constant stream of input; I mean -- imagine life without an eternally-looping soundtrack! You'd have to pay attention to traffic around you (both on foot and in the car), or make sure you didn't run over the granny in Giant foods because you didn't see her stop (you were too busy grooving, eyes closed) or hear Wayne the Bag Boy holler a warning.
(I actually saw someone almost get mashed into a red paste in BJ's because they had their iPod on and didn't hear the BEEP BEEP BEEP of a reversing forklift. To be truthful, I was rooting for the forklift.)
With all the earpieces and ear buds being inserted constantly, you'd think their ear canals would end up with some form of rot or jock itch.
Actually, it's what I am wishing on them. "I'm sorry, sir, but you have some kind of syphilis of the ear canal. We'll have to rout it out with rusty barbed wire, and have this hobo, who has eaten a pound of Bhut Jolokias, piss in your ear three times a day until it clears up."