Chia Keyboard.

Take one standard keyboard, add some cotton or other absorbant material, sprinkle in a healthy dose of chia seeds, and Voilà … you have your very own Chia keyboard. Looks like a great prank to pull on office mates, just make sure to water lightly, and only with the power off. Link (note: ads may be NSFW) – Thanks John!

And here’s another site offering some instructions on creating a similar keyboard garden