This is a model of Wall-E that I downloaded from the Google 3D Warehouse, opened in Sketchup, exported as a .stl file, and scaled to fit in a Makerbot using Blender.

This is a derivative work from this source: http://sketchup.google.com/3dwarehouse/details?mid=762c2dc7e913b39c72c88ac8eac6909c&prevstart=0

It is covered under Google's 3D Warehouse license: sketchup.google.com/intl/en/3dwh/tos.html

Specifically,

Your Rights

Google claims no ownership or control over any Content submitted, posted or displayed by you on or through the 3D Warehouse. You or a third party licensor, as appropriate, retain all patent, trademark and copyright to any Content you submit, post or display on or through the 3D Warehouse and you are responsible for protecting those rights, as appropriate. By submitting, posting or displaying Content through the 3D Warehouse, you grant Google and its end users a worldwide, royalty-free, non-exclusive, perpetual license to exercise the rights in the Content, as stated below:

1. to reproduce the Content;
2. to create and reproduce derivative works of the Content;
3. to display publicly and distribute copies of the Content;
4. to display publicly and distribute copies of derivative works of the content.

It looks similar to a CC-BY-NC-SA license.

I copied the above text (except for the location of the 3D warehouse file and the first paragraph) from here: http://www.thingiverse.com/thing:913