Thanks for mentioning F.lux. I recall reading about it a while back but never tried it. I'm planning to install it tomorrow.
I did a quick search for an iPad equivalent, but nothing promising turned up. I'll keep looking. Much of my evening and night reading is on the iPad and I've wondered if the 'glow' has been disrupting my sleep.
If anyone has suggestions for non-jailbroken iOS devices, please share. Thanks.