I haven’t played with Terragen much yet, but I’ve been thoroughly impressed by some of the work various people are doing with it. If you’ve never seen Terragen artwork, well, wow! It can generate some of the most photo-realistic scenes I’ve seen. And it’s free. Granted, there’s newer, more powerful programs out there now, but in good hands, Terragen can create some amazing stuff (and in the wrong hands, yikes!).
Anyway, check out any one of these sites. They’re some of the better ones I’ve stumbled across:
And, speaking of wrong hands, here’s my first shot at a Terragen scene. I call it Grand Pass.