switching between 2 images

Hi there,

I am trying to display 2 alternating image. I was thinking of some sort of 'screensaver' hack that switch between 2 images, or an auto start an image viewer and let the kindle to sleep back... Can the kindle turn on Automatically? I mean via a script while 'sleeping'?

If not the kindlet way could be the way to go, loading 2 images and alternating between both...

Any creative idea on this?