We've rigged this ceiling tile up to a fishing line so we can slide it away and dump confetti on a coworker's head.
Top photo: We're concealing the fact that the tile is slightly off because one end is clipped to the fishing line. A "welcome back" sign works nicely.
Bottom photo: Huge pile of confetti on top of the tile. The paper underneath the confetti is hooked to the rail on the right. The tile will slide to the left out from underneath the paper.