The convergence of several technological systems (especially nanotechnology, biotechnology, information technology, and robotics) has now been adopted as a strategic goal by several countries, most notably the United States and those of the European Union. The anticipated benefits and related fears of competitive disadvantage have brought together a wide range of interested parties, governmental and nongovernmental. In the rush to enter and/or dominate this arena, the benign promise of converging technologies (CT) are highlighted, although a range of risks and less welcome (if difficult to quantify) implications are at best understated. What, then, are the prospects for exercising governance over the technological systems we are busy creating--and the uses to which they might be put? What will it mean to speak of "global governance" in a world in which the technological promise of CT has been fulfilled?