depending on what type of helpdesk system you are using, (database related or not), you could build a webpage that pulls the data from the database and just have it auto-refresh at whatever interval you wish. You could have it change the background color to red for items that are critical, etc.
You could accomplish this with a second monitor on your PC or have a smaller, less powerful PC, witha single monitor hooked up to it to display the information. It really is just as simple as a monitor to display what ever application’s data you wish to display, a web page like mentioned before would be one, but you could display several applications’ data on the screen as well, like a MS project file, excel spreadsheet and/or a powerpoint presentation.
Airport systems are basically large versions of what has already been described. Somewhere in the depth of the airport is a bank of computers with software running on this which displays the flight information on the screen. They then have TV out cards hooked up to them which then send the video signal to a Coax cable which is run throughout the airport just like the TVs in your house. Each TV in the airport is then tuned to a specific channel. Every once and a while when I’m at the airport I’ll see a good old blue screen of death on the airport monitor showing exactly what it’s running.