From around the net:
The white ones are Oscar de la Renta and Pnina Tornai
http://coolspotters.com/clothing/proenza-schouler-spiral-striped-long-dress
They only used striped fabric cut on the diagonal, not spiral seams :-)
http://www.lovemydress.net/blog/2012/01/so-loves-vintage-win-100-voucher-to-spend-online.html
This one does use spiral seams but only on top!
http://dollsoutfits.blogspot.com/2011/05/spiral-dress-for-14-kish-doll.html
And that links to a doll pattern for sale:
http://www.dolloutfits.com/patterns/robespirale/index.html
Not sure if I've shared this before. There's Farrah Fawcett in a white gown that is the ideal spiral shape.
Here's a spiral seams wedding dress, called "Rae" by Priscilla of Boston
For some really pretty spiral skirts and dresses, check out the brand "Sacred Threads" on ebay.