Researchers have invented a microscope that's about the size of a tiny iPod shuffle, and say the cheap, disposable, and sturdy device could be a boon for doctors in the developing world. The microscope, which researchers say could be mass-produced for about $10, could be used to quickly scan a patient's blood for the parasites that cause malaria, sleeping sickness, and other tropical diseases, for example. The new tool could be a useful alternative to the typically bulky optical microscopes, in which