For a limited time you can get Bryce 5 for free! This deal is running until September 6, 2006 so jump on it while you can. They have both the Mac and Windows versions available to download, so this is an excellent (free) way to create your 3D projects.
Once you’ve installed your copy, check out some of the tutorials to help you create some nifty 3D masterpieces.
Link to Get Bryce: