Thanks a lot for all your links :)

I definitively have to install him Sketchup, the wrong side is that I have to learn it a litte bit myself before, and to be honest it's not the kind of software I like.
That's said, some works done with sketchup are really amazing (the black hawk !!!!!!), proving again that the soft doesn't really matter, the artist/user does.

The physic engine for sketchup seems to be quite fun too, I will dig in it this weekend.
Thanks again !