We've posted the couchmouflage, catmouflage, carmouflage, and satmouflage before, but the Brits got 'em all beat. In fact, they're so well camouflaged you just have to take my word that there are two - TWO! - British soldiers in this picture.
Found at Modern Mechanix (Jul 1939)
Rule 1: Don't stand up
Unfortunatley, he's taken a rather obvious cover...
Remember the first rule of misdirection, meg: always claim what you're not.
And ted - excellent idea, How Not to be Seen was on Neatorama previously here: Link.