In the October 2005 General Conference, Elder Jeffrey R. Holland addressed the young women of the Church specifically, saying:
"I make a special appeal regarding how young women might dress for Church services and Sabbath worship. We used to speak of “best dress” or “Sunday dress,” and maybe we should do so again. In any case, from ancient times to modern we have always been invited to present our best selves inside and out when entering the house of the Lord—and a dedicated LDS chapel is a “house of the Lord.” Our clothing or footwear need never be expensive, indeed should not be expensive, but neither should it appear that we are on our way to the beach."
Some people contend that this is a clear condemnation of flip flops, while others think it refers to all sandals, and others think it just refers to a manner of dress and no specific article of clothing or footwear. I've heard some women complain that flip flops are unacceptable, but when you put a tiny bit of a heel on a flip flop, suddenly it's a dressy shoe--but they can't wear heels. Where do you draw the line?