I've carried out a few practical jokes in my time, anything from filling someones car with "Fart Bombs", hiding someones car and making out it had been towed, calling up work and asking about some obscure piece of hardware and then firing up upon being told they didn't know what it was to wrapping a brick and giving it as a present. Nothing spectacular, but I had a good laugh. Although, the fart bomb incident left me with a nasty scar on my arm, but hey, it was worth it.