I just love Sketchfab, which is a 3D browser based viewer, which you can embed, as here, on loads of different blogs or websites, although sadly not G+ at present, which would be really welcome.
As a means of viewing and collaborating on 3D projects, without needing expensive 3D programs, this is so helpful.
Sketchfab supports most of the most popular 3D file formats.
This is just a test 3D .obj file of some leaves, created in Sculptris.
Click and hold to view, right click to zoom.
