The iPod is best known as an instrument of solitude -- unless the user ignores standards of etiquette by invading the eardrums of fellow commuters, office mates or other innocent bystanders. Then it starts to get annoying. Especially when you're stuck in close proximity.
Amped to its highest volume, the iPod is not nearly as invasive as the classic loud cell phone conversation. But it can have its moments. Like when you're standing in an elevator at 9 a.m. and a co-worker cranks up Amy Winehouse's Rehab. (Too early for that song.) Or when an ear-budded subway rider belts what sounds like a Whitney Houston tune with careless abandon, causing other riders to inch away or flee into another car altogether. (True story.)
"I've heard that problem quite a lot, people singing along," said Leander Kahney, managing editor of Wired magazine's Web site. "And, of course, my kids -- when they have the iPod in, they shout. They don't realize with the headphones they're being too loud, so they'll conduct conversations without taking their ear buds out. And they're yelling."