What can you buy with $26? A pair of movie tickets? A round of beers at the local pub? Maybe a half of tank of gas for your car?
How about lasting change?
Rye Barcott, a former US Marine and the author of "It Happened on the Way to War, " has witnessed first-hand the transformative power of a mere $26 investment.
In the summer of 2000, Barcott was an undergraduate living in Kibera, one of the biggest slums in the world located in Nairobi, Kenya.
Home to over 700,000 people, this densely populated community lives in 10 by 10 foot shacks on a patch of land the size of New York's Central Park.
Every day it's a struggle to meet the basic needs of food, clean water, waste and sewage sanitation -- and sometimes, even just shoes to walk in.
"What defines this place and what you'll often recognize when you first step in is the depravation of it," Barcott told ABC News. "It's jarring and it's overwhelming."
The average daily income is only $1.25.
Outraged by the poverty he saw in Kibera and the cycles of violence it created, Barcott - a student at the University of North Carolina at the time - wanted to make a difference. He was baffled to see the lack of proper healthcare - let alone, sufficiently trained healthcare workers in the region where infectious diseases were rampant and basic vaccines far out of reach.
"In our world of plenty, there is no reason why a child should die of pneumonia. There's no reason why a child should die of not having safe drinking water," Barcott said.
Chance Meeting Turns into Lasting Change
That summer more than a decade ago, Barcott met a local woman who shared his vision of creating change in Kibera. She asked the American student for a small loan -- just $26.
"Her name was Tabitha Festo. She was 34 years old and a widowed mother with three kids," Barcott said. "I had made it a habit not giving out money in part for my own safety and in part because I just didn't know where to begin, but she had a plan."
Tabitha, an unemployed nurse at the time, shared her dream of opening up a community medical health clinic.
"She had conviction in her voice and at the end of the day it was just $26. I handed her the funds and didn't necessarily think I'd see her again," Barcott told ABC News.
Upon his return to the United States, Barcott graduated college and joined the Marines where he was deployed to war-torn countries like Iraq, Bosnia and to the Horn of Africa.
Even while leading Marines into combat, Kibera remained heavy on his mind. A year later Captain Barcott returned to the slums and crossed paths with the woman he thought he would never see again.
"Tabitha found me and took me to her 10 by 10 which she converted into a small medical clinic," he said. "And that was really her dream."
Together, the American Marine and the unemployed nurse created a nonprofit called Carolina for Kibera (CFK) – which invests in local leaders and provides basic medical care to mothers and children in the slums.
Tabitha passed away in 2004, but today the Tabitha Medical Clinic which started with just $26, now serves more than 40,000 patients a year.
"Just imagine what you can do with just $26 in the hands of a remarkable person in a place that is often neglected," Barcott said. "Tabitha shows other residents of Kibera that it's possible. You can have all the odds in the world stacked against you. You can be a widow with 3 kids and no job in the world's largest slum, yet you can also make an incredible impact."
Take the 26 Day Challenge
The Tabitha Clinic and CFK's work have inspired an army of youth leaders to take ownership in transforming the slums - whether through after-school sports program, waste management coalition or through the clinic's focus on maternal and child health.
"We just launched a 26-Day Challenge and this is a challenge where you can adjust your life in small but significant ways to reflect conditions in communities like Kibera." Barcott said adding, "I think that's important because it's a step towards empathy. It's a step towards better understanding of how the majority of the world lives and that's important so that you can be a better informed citizen of the world."
For many Americans, it is hard to imagine what life is like in one of the world's biggest slums. The comforts and luxuries we enjoy and often take for granted are never more amplified or appreciated than when we are challenged to go without them...even for a day. Such is the message of The 26 Day Challenge, a call to action issued by Barcott for Americans to adjust their lifestyles in small but significant ways for 26 days.
"Some of those challenge items involve things that require some deprivation and range from washing your clothes in a bucket of water to more communal things like cooking a meal for your neighbors even though you might not know them," Barcott told ABC News.
For those who have hectic schedules and the idea of committing for 26 days is close to impossible - there is a 24-hour option called Kibera for a Day.
People across America have been taking part in the challenge and some have sent in video of their day-to-day experience with the challenge ABC News.
The main message Barcott hopes the public will take away from the challenge and his overall journey as an agent of change is to "expose yourself to how the majority of the world lives," he urges. "And I think you'll find that it's tremendously inspiring and you'll have a better appreciation for the ways that small amounts of investments can have transformative effects in the lives of others."
Take Action: Think you have what it takes to take on The 26 Day Challenge? For more information and how you can get involved, visit The Million Moms Challenge.