2.8 inch Adafruit TFT touchscreen inserted into what used to be a novelty radio, running a bit of cobbled-together Python software in Raspbian on a Raspberry Pi B+ to display internet time/date, with weather and forecast from weather.com. The white stuff showing through either side of the screen is Sugru helping to hold it in place.
The mini iMac/Pi has wifi and requires only power to start up.
Help from too many internet sources to list here is gratefully acknowledged, contact me if you would like the details. Oh and thanks to my daughters who gave me the screen for Christmas!
PS The Pi is too big to fit in the "iMac" case. You can glimpse it on the left in the background, connected by a GPIO cable. I might make a stand out of Lego and stow it underneath, as the cable comes out of the base of the mini iMac, where the batteries used to be.