I bought a little card for the Raspberry Pi, it's a matrix of LEDs, in a 9 by 14 array, costing £20. It's nice for a scrolling display, driven by a Pi. It arrived today, so I immediately got busy with it. It was a doddle to get working; you just send it text commands out of the serial port, and you can make it do anything. Well, anything that you can do with a matrix of 9 by 14 LEDs. My first effort was to make it display "Hello world". Of course.
I've got it set up as a scrolling display that shows me the outside temperature (currently it's reading 30 C). But if I get more than a threshold number of server alerts (currently set to 200) then something has gone badly wrong on at least one server (or it might be a comms issue), so it interrupts the temperature display to tell me how many alerts there are right now, and keeps showing that number.