Day 1: Mongolia

In Mongolia's wind-torn steppes, field nurses must sometimes travel for days to attend to their geographically scattered patients. A government program will test if PDAs can help nurses treat nomadic patients.

Day 2: Argentina

Horses drink from contaminated streams in Argentine slums, and people aren't always much luckier. Stanford Ph.D. student Rebeca Hwang toured this neighborhood while researching to get more poor people clean water.

Day 3: Nigeria

Forty Nigerian children rip open the plastic wrapping on laptops they received from Nicholas Negroponte's One Laptop per Child (OLPC) project. The OLPC plans to release 15 million laptops worldwide.