This thread is intended so that users can post links to any modelling resources they bump into; mel scripts, plugins, reference images, etc...

When posting please write a short description of what others can expect to find and a link using the BBC url tag -

This thread is not intended for tutorials as there is a seperate forum for these.

Here's one to get started:

Many free scripts / tools and useful utilities to be had on http://www.highend3d.com

Here is a great site for blueprints of real life vehicles.
Cars, jetfighters, helicopters, ships, you name it!

http://www.suurland.com/

This site offers tons of animal pictures, no perfect orthographic views, but nonetheless a great resource for image reference.

http://animals.timduru.org/dirlist/

MJ Polytools:
http://www.maya3d.dk/Scripts/MJPolyTools/

Although most of these tools have been included in Maya 7 (If you have a version below 7, this tool is a must download) I would still get it for the Edgle Loop Split alone. Amazing tool that is. It splits any object along an edge into half and works great in combination with Bevel to create multiple even splits. You hardly ever use the Split Polygon Tool again after you have discovered Edge Loop Split.