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)
Woah, hey, cool! Thanks!
FYI: http://forum.daz3d.com/viewtopic.php?t=42596
http://www.download.com/Bryce/3000-6677_4-10574334.html
sweet, always wanted to try this app out, but never had the funds.