GIMP Plugin Registry

This script adds a realistic film grain effect to a black and white or toned image. To install, copy the attached file to GIMP/share/gimp/2.0/scripts. The larger the file you are running it on, the larger the value you should have for Strength. The value for Sharpness depends on your preferences, but I usually start at 1 and go from there. The lower the value, the sharper the noise.

This script simulates the Lomo effect.
Copy it into the scripts folder from GIMP, you will find it then under Filters -> Light and Shadow -> Lomo.  read more »