With the recent advancements in atomic manipulation techniques like scanning tunneling microscopy (STM), scientists can now theoretically arrange individual atoms to create entirely new materials with specific properties.  If we can achieve precise control over the arrangement and interactions of atoms, what are the ethical considerations involved in engineering life at the molecular level?  Should we attempt to synthesize entirely new forms of life with designer properties, and if so, what safeguards would be necessary to prevent unintended consequences?