I have yet to try gradient mapping but will have to give it a go. Is there a tute for that somewhere? I like channel mixer, but find in certain situations that using Photoshop's Hue/Saturation dialog can give you some nice control over the outcome. In the dialog, desaturate the image completely, then go to the different color channels and try sliding the Lightness adjustment left or right to see how it effects the image.

Kort Kramer - Kramer Kreations