Well first the smartest thing to do would actually get off the earth, so i would get a god damn rocket and fly to some random planet for a while. But of course i would bring the hottest girls in the world to come with me, so then after a while we will fly back to what's left of earth we will have to repopulate....even though that might cause some really funky genetic mutation because of only one father....
meh, that's what i've got, but th0rny's idea doesn't sound too bad