There is another prog very easy (and free) Google Sketchup and interfaced with Moi! (format export SKp)
Same easy ergonomy than Moi! Learning curve 15 minutes! Push Pull staring :)
Kids are crazy about! (see my thread http://forums.polyloop.net/2d-3d-diverse/10495-google-sketchup-6-a.html
(in french for some articles) :)
And incrediblely powerful for architecture! And with a lot of plugin for anything!
And any 3D models directly in the prog from 3Dwarehouse
Some animations are possible (camera animation)
And with another plug SketchyPhysics2 (free) you can make remake of Halo training camp!
Making of : Copter: http://www.sketchucation.com/forums/scf/viewtopic.php?f=81&t=12513&st=0&sk=t&sd=a
Making of : reaction plane
http://img254.imageshack.us/my.php?image=image5iq1.png
http://img247.imageshack.us/my.php?image=image5jp6.png

http://sketchup.google.com/3dwarehouse/details?mid=9c748490e0e1d378522b1d41b4aa7acc&ct=mdrm&prevstart=0
(for play it SketchyPhysics2 must be installed)


And for rendering there is a plug Podium who is the more easy render that exist !
Only 2 cursors!!! (free for 500*500)

Living By Biebel (Ketchup + podium)


Object 3D Wharehouse by me ;)



Robot (Ketchup + Podium) By Solo

http://sketchup.google.com/intl/fr/
http://sketchup.google.com/3dwarehouse/
http://www.suplugins.com/ (Podium)
http://code.google.com/p/sketchyphysics2/