What a great weekend it was, with some sunshine (finally), fun with friends on the lake, enjoying nature at its finest. I think I'm obsessed with the Okanagan, can't talk enough about it, and it must be getting on the nerves of the people I know.
Yesterday we were out at the cabin, and Danny Hauptman was asking why all the outhouses there have little moons cut out of them. A great question Danny, and I've found an answer for you. There is actually a book called The Vanishing American Outhouse by Ronald S. Barlow (1989), that expands a bit on why you see half moons on outhouse doors:

"Luna, the ancient crescent shaped figure, was a universal symbol for womankind. A moon, sawed into a privy door, served as the 'Ladies Room' sign of early innkeeping days. Sol, a sunburst pattern, was cut into the men's room side of the outhouse. These symbols were necessary because in Colonial times only a fraction of our population could read or write.

"As time passed by and frontiers were pushed further westward, the gentlemen's restrooms fell into disrepair and eventually were abandoned altogether. Accommodations for ladies were better maintained and this is why the moon symbol remains on many outhouse doors today. Its original meaning, however, was lost to the general population sometime in the mid 1800's."

So there you go, the moon was a symbol for the ladies' outhouse, and was probably also harder to cut out a "sunburst" pattern in wood than a crescent moon. For more FAQ's about outhouses, check out this page.