hey, all. I did a search on the orientation issue and found that upside down is the only supported feature, and is only available on certain hardware.
I use the sansa, and wanted to point out that sansa's LCDs are natively alighted to be viewed in landscape mode, and so somehow being able to switch to landscape would greatly decrease eyestrain. Currently, viewing in portrait mode, you get different contrast levels in the left and right eye, causing lots of strain. I'm not even sure why sandisk designed it like that in the first place...
But anyway, I just wanted to bring that to attention.