There are many complex phenotypes/strains that are desirable for practical applications in the context of Cellular or Metabolic Engineering. One example is when one desires to endow a platform organism with a biosynthetic or catabolic pathway that another organism may possess. Such a pathway may involve several enzyme-coding genes as well as regulatory genes, but these genes may be unknown. Another example is the ability to endow a platform organism with unusual membrane structures or a stress-response system that some other organism possess. This would be important in bioprocessing and advanced bioremediation applications. Endowing cells with such desirable capabilities requires several or many genes deriving from other organisms, as for example is the case of employing metagenomic libraries for generating desirable strains. Thus, the ability to generate hybrid organisms, here called Biological Alloys, is an important biotechnological goal of practical and fundamental significance. An interesting and likely scenario is that by combining large sets of genes from two or more different organisms one can generate novel synthetic phenotypes that are not merely additive phenotypes from the two (or more) donor genomes, but rather "synthetic" amalgams, like in metal alloys: novel, not previously existing or predictable phenotypes. I will discuss our work towards this goal.