Icomic for mac
 

I've started using I comic to help me plot visually my storylines. I find a few renders and put them down on the page. As I write I condense or add directly to the caption boxes. The big advantage here is the visual aid, at least for me. If I can see the location, especially for blocking, it helps me keep track.

Any screenshots for examples?

I too believe visual aid can be a great tool for keeping your creative mind sharp! I also compose music to display the emotions felt in the scene. I record synth lines or pads with my midi keyboard and sequence them. I think that helps me. I feel that the soundtrack to what will eventually be a movie (animated or not) is of equal production importance as the visual pieces!