ROTOBox is a utility to setup image references for mesh design. The references are set up in 3D space and are available in all views. The UV planes can easily be adjusted in position to best fit modelling requirements

Download ROTOBox v1.3 2006-01-23 -
[1] Prepare reference images. The side/bottom/top views should be aligned in the same direction as should the side/front/back views. The images are aligned at the corners indicated in the diagram - when triming your references try to ensure the indicated corner is as acurate as possible. The other edges can be as sloppy as you like since each reference is scaled appropriately.

[2] Load the script in to the text editor and run using alt+p. Alternatively load the script in to a default script location and run from the script window.

[3] Select your reference images. Select as many as you require - blank images are ignored as are invalid images.

[4] Select desired scaling. A grid unit is defined by the distance between lines in the grid displayed in the 3D view window.

[5] Select Create. This will create a UV'd plane for each image you selected.

[6] To see the images select alt+z. Create a new mesh and set drawtype to wire in Object buttonsF7. Start modelling!

The image references correspond to the following blender 3D window views,
Top view : F7
Bottom view : ctrl+F7
Side view : F3
Front view : F1
Back view : ctrl+F1

Example Images
Top view of mini cooper
Side view of mini cooper
Front view of mini cooper
Back view of mini cooper

corner alignment of reference images

screen shot