Here's the effect I'm talking about. The final result I want is at the BOTTOM of the post.http://www.gimptalk.com/forum/viewtopic.php?t=969
We'd want the effect to be much slower though, and to start in the bottom left corner and go around each side and end at the top right corner.
The pictures you'd be working on aren't anything unusual. Just product shots.
Let me know if you need anything else!