How do I create two UV coordinates...

Support Materials and Textures
1

…for the same surface? I ask because I wanted to create one UV mapping for the texture on an object, and another mapping for tangent shading.

2

You can find the information here:

http://www.blender.org/cms/Composite__UV_Map__ID.830.0.html

You have to use a CVS version at this point because it is not officially released yet.