Many of us get frustrated at a concert or show by all the people who've got their mobile phones out, sometimes blocking the event.
Now one man thinks he's got an old-fashioned solution to this 21st century problem.
In their attachment to their smartphones, the students at Mercy High in Burlingame, California are typical teenagers.
But when they enter Ryan Offield's English class the phones get locked into little bags, which can't be opened until class is over.
"By separating something that's primarily for their social life, I'm hoping that it brings them more in the moment," Mr Offield says.
These bags are made by a start-up called Yonder. Its founder, Graham Dugoni, is attempting nothing less than breaking cellphone addiction.
He says he thought a new etiquette was needed for the digital age.
"Just something to help people engage with each other in a real way," he says.
"What it symbolises is a movement, and the bag is just the tool."
The Yonder pouch locks much like a security tag in a clothing store. If someone needs to access their phone, they can choose to leave the phone-free zone.
The Yonder bags are now mandatory for everyone attending a performance by comedian Dave Chappelle.
"We've had a strict no cellphone rule for years," he says. "Obviously if you look on YouTube you'll see very few people adhere to it."
Before the bags, Chappelle often found himself telling jokes to people distracted by their devices.
"It would be very hard for you to talk to anybody if he was [on his phone] the whole time you're talking."
Back at Mercy High, junior Daniela Clinton had to bag her phone for three days on a school retreat.
"I could hear it vibrating! But I couldn't grab it and use it," she says. "I hated it so much."
But she was able to see the benefit when it was over.
"It was like a break from reality. I completely forgot about everything, even school, and that was nice."
It's an old-fashioned solution to a 21st century problem.