It was pointed out to me that there is a
free registration at the
PhotoSIG site, which does allow you to view the full size images.
The site does not have a search engine at present, but you can use a
Google site restricted search as a reasonable alternative.
Certainly worth checking out are the
portfolio of Dutch photographer jaaphart/Jaap, and
Stevenshof Windmill.
The site also helped me to find Foto Natura which is a Dutch
picture agency, with a number of windmill photos. The images are dual captioned in English and Dutch, though you will
find more results if you search for windmolen than you do for windmill.
Update:
[17/8/04]
It's been further pointed out that the keyword categories on the Foto Natura site are not very well done - if you search for
"mill" or "molen" then you will get a much higher number of windmill photos.
See also:Sepia photo of Pitstone windmill
(4/8/04)
Photos at the PhotoSIG site and Foto Natura