This script simulates a high quality (portrait) photo like these from the National Geographic.
Copy it into the scripts folder from GIMP, you will find it then under Filters -> Generic -> National Geographic.
Thanks to Martin Egger for the shadow revovery and the sharpen script, which I included in the script.
Examples here and here:



Update1: Added local contrast option.
Update2: Optional inverted layer mask for brighter skin types.
Update3: Added a batch version of this script, run it with
gimp -i -b '(elsamuko-national-geographic-batch "picture.jpg" 60 1 60 25 0.4 1 0)' -b '(gimp-quit 0)'
or for more than one picture
gimp -i -b '(elsamuko-national-geographic-batch "*.jpg" 60 1 60 25 0.4 1 0)' -b '(gimp-quit 0)'
Be careful, the batch script overwrites the original image. More info here:
http://www.gimp.org/tutorials/Basic_Batch/
Update4: Fix for the batch script, it merges now all layers before saving.
Update5: Extensive internal fixes. Better defaults. And all edits are executed on extra layers.
Update6: Batch script also updated.
Update7: Two tinting options, red and blue.

For all scripts together, go here.