LCD monitors' bases are already rotatable from portrait to landscape. But it isn't motorized.
I propose an LCD monitor base which rotates automatically. When viewing a slideshow of photos, both landscape and portrait photos would be FULL screen.
The photo viewing software would need to be updated, and a hardware driver installed to control rotation motor.-- knowtion, Dec 06 2009 Why not?-- DrWorm, Dec 06 2009 Or a huge circular LCD screen.-- hippo, Dec 06 2009 Or a rubber screen that could be stretched to any aspect ratio required.-- pocmloc, Dec 06 2009 Won't this put monitor-turners out of business?-- leinypoo13, Dec 06 2009 One of those wooden backscratchers and some duct tape, put it on a landscape/portrait alternate slideshow of your holiday snaps, and you could use it to pet the dog and induce sea-sickness in unwanted guests at the same time.-- random_patenter_syndrome_victim, Dec 06 2009 There are digital photo frames that do this. Some are wall- mounted and some sit on a table. I think I've posted links to them on some other idea that's pretty much the same as this one.-- notexactly, Dec 18 2018 random, halfbakery