Digital picture frames could be very useful as annunciators if a host computer could at least tell them "switch to picture x now". Even better would be the ability to download a new image and display it immediately. Think of it as a slow frame buffer.
There are now 15" versions, and even those little keychain 1" displays might be useful.
Web searching shows that the documents on most frames are unhelpful or nonexistent.
A cheap notebook computer could be made to do this. The digital picture frame advantage would mostly be form factor. Power consumption and price are lower than a notebook for the smaller versions.
Are there any digital picture frames that can be controlled by a host computer via USB or Ethernet?