Eyestrain comes from viewing something with a backlight. As I understand it, Pixel Qi displays have the option of turning off the backlight and enabling their tech that reflects light back through the LCD (like a piece of paper, etc).

Ah, ok. My Nokia phone has a reflective screen, but I've never really thought about the difference in eye-strain when I look at it indoors and in direct sunlight. Hm, I have to go test it. :-)

You'll still have some amount of eyestrain, but no more than reading text on paper, or looking at photos, IIRC.

I find it helps when I put my iPad into white-on-black mode when using the Kindle app.

A daylight readable iPad would be awesome for traveling. How about something like an iPad with front and back cameras? One could run a Google Maps-like program with add-on features that makes it an interactive travel guide. Hold it up to take a photo of a landmark, and it could automatically create an inset picture and upload it to a photostream. Come to think of it, this would make a great feature for an iPhone 4 app.