On Facebook I keep seeing ads for Bonsai, a company that apparently makes "high-quality" sheepskin-lined flip-flops, which they promise will "keep your feet warm in winter and cool in summer."
I don't know where these people are spending their winters, but I'm reasonably certain that merely standing on sheepskin is not enough to keep your feet anything like warm here in Colorado. Maybe on a nippy summer evening these would be nice, but that's about it.
I guess these sheepskin-lined monstrosities solve the problem that causes people to wear sandals with socks - wanting that little bit of extra warmth without having to go so far as wearing a real shoe. You can't wear socks with flip-flops, so you get sheepskin instead.
I am not a shoe snob like Sally and I don't mind seeing people's toes or anything, but I have to admit I am a little bit surprised how widespread flip-flops have become as all-occasion shoes. When I was a kid I think we only wore them to the pool or beach, and now you see them absolutely everywhere.