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 complete exposed 35mm film strips with frame numbers, lettering, overexposed sprocketholes and DX film edge barcodes .
Copy it into the scripts folder from gimp, you will find it then under Filters -> Decor -> Photo with Sprocketholes.  read more »

This script simulates the cut-off of the first picture of a film roll of cheap cameras like Lomo. Role model was this picture from flickr.
Copy it into the scripts folder from gimp, you will find it then under Filters -> Generic -> Photo Border.  read more »

This is a script which simulates the typical film grain of high ISO pictures. I scripted exactly this description. Copy it into the scripts folder from gimp, you will find it then under Filters -> Generic -> Film Grain.  read more »

Add adding realistic film grain to BW images

Description for PS: http://www.outbackphoto.com/workflow/wf_95/essay.html