Products such as the facsimile machine, the video recorder, and the personal stereo are the fruit of numerous incremental developments in technology. Our ability to forecast the "what and when" of such incremental technical innovations is satisfactory, although the prediction horizon stretches barely seven years. We are not so good, however, at predicting the what, let alone the when, of technical quantum leaps requiring scientific breakthroughs. Examples from the past are the transistor and the laser; future possibilities might be bio-implant communications devices or robotic pets.