Zimbabwe's President Robert Mugabe (left) greets South African President Nelson Mandela in Harare, Zimbabwe, in 1998. The two men have shaped their countries in dramatically different ways. Rob Cooper/AP hide caption

itoggle caption Rob Cooper/AP

A well-wisher uses his phone to take a picture of a banner of photos of Nelson Mandela outside the Mediclinic Heart Hospital in Pretoria, where the former South African president is being treated. Ben Curtis/AP hide caption

itoggle caption Ben Curtis/AP

When Barack Obama was a U.S. senator in 2006, he visited Kenya, the homeland of his father. He's shown here planting a tree with Wangari Maathai, a Kenyan who won the Nobel Peace Prize. He is not stopping in Kenya on his current African tour, however, a decision that has upset many Kenyans. Simon Maina/AFP/Getty Images hide caption

itoggle caption Simon Maina/AFP/Getty Images

A woman sells bananas at the Kampala Airport. Ugandans eat about a pound of the fruit, on average, per day. Ronald Kabuubi/AP hide caption

itoggle caption Ronald Kabuubi/AP

Sheep graze in the street last year in Cairo. Gianluigi Guercia/AFP/Getty Images hide caption

itoggle caption Gianluigi Guercia/AFP/Getty Images

Kenyans watch a presentation at the "mobile apps garage showcase" this in Nairobi. Gregory Warner/NPR hide caption

itoggle caption Gregory Warner/NPR

Kenyan election observers and voters in the mixed slum of Kiambiu — where the first fires started in Nairobi after the disputed presidential election of 2007 — vote in this year's elections. Could something as innocent as the color of the ballots and ballot boxes be contributing to voting "irregularities"? Gregory Warner/NPR hide caption

itoggle caption Gregory Warner/NPR

Partnerships instead of short-term help: Jean Jumeau Batsch, an obstetrician-gynecologist in Port-au-Prince, Haiti, is collaborating with Dr. Ambereen Sleemi, from New York City, to build a training program for Haitian OB-GYNs. Courtesy of Dr. Ambereen Sleemi. hide caption

itoggle caption Courtesy of Dr. Ambereen Sleemi.

Spotted hyena cubs socialize at their communal den in the Maasai Mara National Reserve, Kenya Courtesy of Deanna Russell hide caption

itoggle caption Courtesy of Deanna Russell

Askinosie buys beans directly from small farmers. The goal: better quality control, and more cash to the growers. Bob Linder/Courtesy of Askinosie Chocolate hide caption

itoggle caption Bob Linder/Courtesy of Askinosie Chocolate