Take a peek at the world of tomorrow. Science News has published an article on synthetic biology: Digital Cells. Synthetic biology does not refer to “inventing life” from scratch. It also doesn’t mean simply simulating life on a computer. It is concerned with starting with a simple model organism and understanding it well enough to bend it to your purposes. As Thomas Knight of MIT says, referring to building genetic circuits on demand, “We want to move away from the situation where you build the system and pray that it will work, toward the situation where you build the system and, unless you’ve done something stupid, it will work.” We will be programming living organisms the way we program computers right now. “Eventually, the goal is to produce genetic applets,” says Timothy Gardner of Boston University, “little programs you could download into a cell simply by sticking DNA into it, the way you download Java applets from the Internet.”
Downloading life from the web isn’t as far-fetched as it sounds. Last summer two scientists succeeded in synthesizing the polio virus from basic chemicals and a file they downloaded from the Internet. As one of them said, “We don’t need any nature-formed template anymore. We just need the Internet to tell us the sequence of a virus. You can make pretty much any virus this way.” Some people have bemoaned the fact that we didn’t destroy the smallpox virus when we had the chance. But now that its sequence is available for download, it doesn’t matter whether we destroy that last physical version. We can always print more.
Rambles Blog at Star Chamber 
We’re already doing this sort of thing in organisms much more complex than bacteria. One of the members of my old lab inserted a rather complicated genetic program into some mice. When fed a specific synthetic hormone, a DNA recombinase (editing enzyme) is activated in a specific population of cells lining the lungs. This enzyme then mutates a specific gene in the genomes of these cells, such that they become tumerogenic. The problem is that it has taken crossing three separately engineered transgenic lines to get to this point: as Thomas Knight says for the article, “We want to move away from the situation where you build the system and pray that it will work…” Amen, brother.