A new smartphone app gives a close-up view of a patient's eye. Screengrab from video by Peek Vision, produced in collaboration with Sony Mobile. hide caption

itoggle caption Screengrab from video by Peek Vision, produced in collaboration with Sony Mobile.

Our readers wrote in on how they tried to take a vacation from their smartphones. Christian Wheatley/iStockphoto hide caption

itoggle caption Christian Wheatley/iStockphoto

A salesperson demonstrates the Apple iPhone 4 in New Delhi, India. While mobile device use is growing rapidly in emerging markets, Apple's current product line may prove prohibitively expensive for many consumers. Manish Swarup/AP hide caption

itoggle caption Manish Swarup/AP