This is a fun idea that might suit employee engagement leaderboards – make your screensaver the leaderboard. That way you creates more visibility for the competition you are leaderboarding.
I use a MacBook so I used a great little tool called WebSaver which you can download and install on your Mac. Once installed go to Desktop & Screensaver and then in Options cut and paste the Web URL of your leaderboard.
Now, when you pop off for a coffee, colleagues will see the leaderboard each time they walk past your desk.