There are lots of good landscape photos on the net. You could endlessly link to them but I thought this page had a particularly good variety of photos. Very vibrant and plenty of good inspiration for TG2 because I think TG2 renders can end up a bit drab. Photographers nearly always post process. This needs to be remembered.
http://www.photographyoffice.com/2011/09/into-the-light-landscape-photography-by-jay-patel/
Yea those definately look like something Terragen 3 would render. :)