Rotoscope?

[Matthew Hagerty]

Greetings,

How can I set up simple rotoscoping?  Right now I simply need to be able 
to view a background image to work with as a reference, but it would 
also be nice to be able to use video frames.  I have tried setting the 
image as the view background, but it scales with the view.  I have also 
tried to make a material, but again I cannot seem to prevent the mapping 
from distorting or resizing the image to match the object (a simple 
rectangle.)  At the very least I need the image visible in wireframe so 
I can trace over parts of it and scale objects to the correct size 
relative to the other objects making up the model.

Thanks,
Matthew