Grandma IS the recipe for Soylent Green.
Lawl, I'll have to mark that one down in my copy of 'To Serve Man'! +1
Anyhow, no terraforming an entire planet at this point seems absolutely insane, a bit like trying to build a city with a child's shovel at the beach. Mars and the moon are utterly uninhabitable, and they'll be that way for the next hundred years.
The only colonization I can see happening in my lifetime is perhaps some offshoot of the Biosphere project (except working properly, and without Pauly Shore) being set up on other plantets, and then building more and more sealed settlements with metal imported from Earth or later mined from the planet itself.