Been looking for this forever and finally found it!!!!!!!
It's of Milford Sound in New Zealand. The picture was taken from approximately this location: http://maps.google.com/maps?ll=-44.675,167.929444&spn=0.1,0.1&t=m&q=-44.675,167.929444
Unfortunately, this is the ONLY source I could find on the web. 900x506 resolution. It appears it's by an amateur photographer. Anyone care to sign up and grab the high-res version?
Enjoy, it took me forever to find it!
I found the full version here:
If you ever want a high-res image, and do not want to pay for it, download the low-res version, upload it to Google Images search, and tell it to display other sizes. 99% of the time you can get a very high res version for free.