No serious tip today, just a prank tip for you!
Turn a co-worker's world upside down for a laugh.
Because I have no poker face, spend all day on a computer, and am a lame prank puller, this is all I can help you out with on April Fool's Day. Press Ctrl+Alt+↓ to turn the display on a computer screen upside down. (Just press the opposite, Ctrl+Alt+↑ to return it to normal display.)
Now, what is the best prank ever played on you? Are you gullible like me?