Using red filters? When?

What are people's thoughts on when to use the red filter, or if? Simply for shallow stuff?

I search for "red filter" yields the following results:

http://wetpixel.com/forums/index.php?act=S...lite=red+filter

If the link doesn't work, go to the search area and type in "red filter" -- on all forums, any date.

This is probably the best thread: http://wetpixel.com/forums/index.php?showt...0&hl=red+filter