What makes a great prank??

Interestingly enough, it's The Economist that wants to know in Pranks: a competition From Hermes to bonsai kittens!

I concur with... "Abbie Hoffman, a 1960s radical-cum-trickster, [who] said most pranks fell into one of three categories: 'good' pranks were amusingly satirical, 'bad' ones gratuitously vindictive, and 'neutral' ones surreal and soft on the victim (if there was one)."

Give me good, surreal pranks anytime!!

(from Metafilter)