I am new to the gimp mailing lists so first of all I would like to say hi: Hi!
With that out of the way, I would like to present a small project I have been working on with Guillermo S. Romero which I hope may be of some use to people who are fellow animators, or for folks who are into video editing, or for people who like neat stuff: the "gimp-perl for animation post-processing" page:
http://www.ualberta.ca/~cwant/gimp/postprocess.html
This is a collection of scripts that do some fun effects with raw animation/video frames in batch-mode (each script comes with an example movie). Anyways, it was a lot of fun writing these and it gave me an excuse to stop putting off learning perl.
I hope you like the page, and either find the scripts useful, or are inspired to write that great video transition that you've always wanted to see!
Regards, Chris Want
P.S. Many thanks to sjburges for help while writing these!