I've been digging around on this whole modesty and head covering thing. Mostly to see how mainstream it has become.
In my city we have a few Christian/Catholic bookstores. On a whim, I went to three of them. The first was a small Catholic store. They sold mantillas in little plastic baggies. The other store was a non-denom store where they didn't sell any head coverings. The third was a bigger Catholic store where at the front of the store they sold both black and white mantillas and chapel veils (more expensive I might add) hung on coat hangers.
I've seen a few women in my city who wear their hair long and wear long dresses and skull caps. I also went on a trip and ran into a few of these women. So it seems that there is enough of a population of women who follow this belief.
Looking on the internet you also find women who are fasionably modest. They choose to wear more modern looks but wear long skirts and shirts and scarves. They are less noticable then the other women so I haven't really been counting them because they could just be dressed up for a reason (like work).
It seems to be a growing trend. I suppose at this point in my research I would talk to women who follow this belief. I've read several blogs and they all point to religious reasons. I wonder if there are women out there who dress modestly for other reasons. I suppose I will have to do a search on those as well.