While 3D modelling softeare has existed since the '80's, SketchUp was released in 2000 with the tagline 3D For Everyone. The Google version was released in 2006 although is still referred to as SketchUp.
SketchUp holds a Patent U.S. Patent 6,628,279 on its Push/Pull technology:
"System and method for three-dimensional modeling: A three-dimensional design and modeling environment allows users to draw the outlines, or perimeters, of objects in a two-dimensional manner, similar to pencil and paper, already familiar to them. The two-dimensional, planar faces created by a user can then be pushed and pulled by editing tools within the environment to easily andtively model three-dimensional volumes and geometries."
The patent was applied for in November 2000, and awarded in September 2003 (U.S. Patent 6,628,279 ).
On April 27, 2006, Google announced Google SketchUp, a freely-downloadable version of SketchUp. The free version is not as capable as SketchUp Pro 6, but it includes integrated tools for uploading content to Google Earth and to the Google 3D Warehouse, a repository of models created in SketchUp.
The free version of Google Sketchup exports to a number of 3D formats, including Google Earth .kmz files, while the Pro version extends support to include .3ds, .dwg, .dxf, .fbx, .obj, .xsi, and .wrl file formats. Google SketchUp can also save "screenshots" of the model as .bmp, .png, .jpg, .tif, with the Pro version also supporting .pdf, .eps, .epx, .dwg, and .dxf.
Each version, starting on Sketchup 6 has a FaceMe character. These are components which always face the camera, except when being edited. Version 6 came with Bryce. Version 7 came with Sang and version 8 came with Susan by default. As of version 8, Sang is downloadable however Bryce is not if not connected to the internet. Nancy, another character is downloadable but is not on any of the versions by default.