You see them every day, everywhere. Glued to their devices, these pedestrians are busy texting, watching videos or playing mobile games on their mobile phones.
So caught up in their own world, they seem oblivious to what is around them - stairs, other pedestrians or, worse, oncoming traffic.
Motorists are not the only ones who are distracted by their phones. Pedestrians are equally guilty of texting while using the roads and putting their lives at risk.
Dr Philip Koh, 49, a general practitioner who is also the chairman of the medical board at Healthway Medical Group, recalls treating a patient in his 30s who twisted his ankle badly two years ago when he fell into a drain near Upper Peirce Reservoir as he was replying to an SMS.
Dr Koh says: "The bad sprain left him unable to stand or walk for a week."
Dr Lee Kwok Keong, 40, a family physician at Avenue K Clinic @ Punggol, saw a similar case earlier this year in which a woman in her 50s suffered a sprain after she tripped while walking and playing a game on her mobile phone.
"She did not see a pothole in the pavement. Her whole foot went into it and she twisted her ankle."
He says he used to see about two or three such cases a year and this figure has grown slightly to three or four cases in the last year.
General practitioners in Britain have also seen more mobile phone-related injuries in the last year, reported The Daily Mail last Tuesday.
Of the 22 general practitioners surveyed, 14 saw a rise in such injuries, which include bumps to the forehead after hitting posts or walls, and grazed knees after falling.
In the Chinese city of Chongqing, a special "mobile-phone sidewalk" has been set up for pedestrians who insist on using their mobile phones.
Dr Leong Choon Kit, 47, a family physician at Mission Medical Clinic, is sceptical that one can tackle two different tasks simultaneously.
"Even if you don't get into an accident, you can walk into lamp posts or other passengers, board the wrong bus or get honked at by drivers," he says.
Summing up the dangers facing distracted road users, Dr Adrian Wang, 48, a psychiatrist at Dr Adrian Wang Psychiatric & Counselling Care, says: "On the road, a fraction of a second can make a difference, and focusing on your phone delays the body's reaction time.
"Looking at your phone also reduces your field of vision and makes you less aware of things happening around you. As a result, you may not see oncoming danger, such as a car or pothole."
However, those who walk and text say they are confident of their ability to multitask.
Says undergraduate Nur Zahirah Ismail: "I know it is dangerous, but I still do it because I haven't had an accident so far."
The 21-year-old checks her e-mail and social media network every day while walking to class or home. She also replies to messages and listens to music.
She say: "I still know what's going on around me even though I'm looking at my phone. I also remind myself while walking to be aware of my surroundings."
Credit control executive Victor Lim uses mobile apps such as Facebook, Instagram, WhatsApp and Telegram a few times every day while walking on roads and pavements.
Says the 26-year-old: "I look up from my phone and glance around every few seconds, especially when I cross the road."
Still, motorists and other road users SundayLife! spoke to are quick to voice their frustrations with pedestrians who refuse to put their phones away.
Student Raihan Rahim, 20, who rides a motorcycle, says: "I have to honk at them at least two or three times a week. They would walk onto the road right in front of my motorcycle, even if the traffic lights are not in their favour.
"As pedestrians, they are supposed to look left and right before they cross. But these people don't do that because they are glued to their phones."
Bus captain trainee Rickee Ng, 60, adds: "I often see such distracted pedestrians walking head-on towards me on the sidewalk or in the shopping mall. Sometimes, I even have to stop to avoid colliding into them.
"It's irritating, but what else can I do? These people are not breaking the law after all."
It is an offence to use a mobile phone while driving in Singapore. If convicted, offenders may be fined $1,000, disqualified from driving and/or jailed for six months.
From February next year, these penalties will also apply to those who drive while holding and using any type of mobile device, including small tablets.
However, there are no regulations for pedestrians who use mobile devices while they are on the roads.
Road safety experts believe education, not punishment, is the way to go.
Says Mr Gopinath Menon, 70, vice-chairman of the Singapore Road Safety Council: "A pedestrian using a mobile device is mainly endangering his own safety. Hence, the remedy is not to impose penalties on him, but to educate and advise him to look after his own safety."
Adds Mr Bernard Tay, president of the Automobile Association of Singapore: "As with distracted driving, distracted walking may lead to road accidents and this is an increasingly urgent issue that requires addressing."
Distracted pedestrians who paid with their lives serve as effective cautionary tales for some.
An Australian teenager reportedly plunged to his death in a multi-storey carpark in Melbourne in 2011 after walking over a railing by accident while texting his friend.
Horrified by such reports, IT auditor Stephen Lim, 36, stopped texting while walking two years ago.
He says: "It struck me how easy it is to get into an accident while you are distracted. Being able to see your messages instantly is good. But ultimately, my life is more important."
Do you think it is okay to walk and text? Write to firstname.lastname@example.org