Thanks to a comment on an earlier item of mine from someone on the Culture Show (?!), I now know who the artists/photographers in question are! Ari Versluis and Ellie Uyttenbroek are responsible for the documentation of the various fashion tribes throughout the world's major cities from 1994 - 2008. They have compiled the images in a book called "Exactitudes". I love the outcomes when all images are tiled together.
The website looks pretty cool too.
Below - one of their earlier documentations in 2004