artreview.com - http://www.artreview.com/ Social networking site for the artworld. Members are artists, galleries, collectors, critics, curators, art lovers...
Saachi Online Artists - http://www.saatchi-gallery.co.uk/yourgallery/ Interactive art gallery.
artmesh - http://www.artmesh.org/ Private network in the world of fine arts, for artists, art professionals and art lovers. (Sign up possible only upon invitation by a member.)
- http://www.artreview.com/