Confession: I've never actually assembled one of the papercraft printouts—I did glue together about half a robot once before becoming violently ill with laziness—but I'm almost considering taking a go at these Portal turrets.
Confession 2: By "considering" making these turrets, I really mean "lightly toying with the idea."
Confession 3: By "lightly toying with the idea," I really mean there's no way in hell this is happening. I don't even have paper, glue or anything. Right now I'm typing on a pile of rocks fashioned into a QWERTY arrangement. I have no clue if you want even read this.