[blots]

I suppose you could use that for stylistic effect. Like a change of mood in the story, or a changed attitude of the character.

[arethuza]

That's exactly the approach that Douglas Trumbull wanted to use in Brainstorm where the replayed experiences of others would have been displayed using his 60fps Showscan techbology:

http://en.wikipedia.org/wiki/Brainstorm_%281983_film%29

[rangibaby]

The Wizard of Oz did this with black and white / color.

[ianstormtaylor]

That would be really interesting. I could imagine that being used in something like Requiem for a Dream to make things feel slightly off.