For a limited time, you can get Bryce 5.0 for free on the Daz-webpage. Many people like it for making landscape-backgrounds or even architecture.
http://www.daz3d.com
(I hope nobody already wrote about this, but a forum search did not show up any results)
http://www.daz3d.com
(I hope nobody already wrote about this, but a forum search did not show up any results)