Athasian Cartographers Guild.....
The Athasian Cartographers Guild is a group of mappers that have taken on the task of mapping out the entire world of Athas, which is the setting of D&D's Dark Sun Campaign. What they've completed so far is quite impressive, and you can view their efforts by going to:
All the maps are .psd format, so you'll need Photoshop or a viewer capable of recognizing .psd images (such as Quivi http://quivi.sourceforge.net/index.en.html or Irfanview http://www.irfanview.com) in order to see them.
Or my personal favorite (freeware for personal use, no nags, no adware, no spyware) Faststone Image Viewer http://www.faststone.org/FSViewerDetail.htm
Also converts, scale, and corrects in batch, allows image annotation, etc.