A physicist creates a fundamentally new state of matter and foresees that it could one day lead to better superconductors. Meanwhile a nonprofit drug company--yes, there really is such a thing--labors to recycle an old antibiotic to combat a deadly parasitic disease in developing nations. Those two innovations, one a basic discovery, the other a novel application of existing technology, illustrate the breadth of ingenuity recognized by the third annual Scientific American 50. The magazine's Board of Editors has compiled a diverse list of those who during 2003-2004 exhibited outstanding technology leadership in the realms of research, business and policymaking. Most of the members of this year's honor roll are from the U.S., but they also hail from as far afield as India, Ghana and Israel. These awards demonstrate the love of knowledge driving basic research, the entrepreneurial spirit spurring development of, say, a nanotube microchip, and the desire to find new ways to make tiny fuel cells or to use the Internet to assist poor south Asian farmers. All originate from a common need to take what we know one step further.