Here are the before and after shots I took, following the idea in comment 101 ( http://talk.maemo.org/showpost.php?p...&postcount=101 ) to just put permanent marker along the side of the slider nearest the lens.
Easy enough to do with the back off, I went along several times to make it nice and thick.

The top two are off the footpath in the dark, the latter two of the lounge floor under indoor lights. In both, top picture is before the marker pen, and you can see the blue haze, as well as the improvement !