Metering Out Hope

"I'm a nobody," insists Hannes Urban. "I'm at the back of the queue." Try telling that to the street kids he has helped in Nairobi, or the people in Veracruz to whom he brought mobile health clinics and free medicine.

For them, the bearded Austrian taxi driver, 46, is a modern-day Samaritan they call Father. Urban's one-man mission was born in 1998, during his first trip to South Africa. Moved by the homeless of Cape Town, he vowed to raise donations...