Little LED displays are cheap for the Raspberry Pi, and they're fun to play around with as you learn how to use the thing. Case in point, Instructables user botdemy's message board that displays a message sent from a server.
The Pi hosts a web server that translates any block of text into a scrolling LED message. When you type out your message, it shows up on the Pi's display. The bulk of your work you'll do here is setting up the web server, but it's not terribly complicated and it's a great project to learn some of the basics of using the Pi's more connected features. Head over to Instructables for the full guide.
IoT RPi LED Message Board [Instructables]