Cells, gels and DNA strands are the 'wetware' of the twenty-first century. Imagine taking cells from a cancer patient and programming them to be able to detect disease and then prompt the body to cure itself. Or clothes woven with microchips, where nanofibres and living cells combine to form wearable bio-weapons detection systems. Both revolutionary applications are closer than we think. Some scientists are pushing the boundaries even further by creating synthetic biology: the ultimage scrap-heap challenge, where brand new creatures are engineered in the laboratory.