Ooohhh, you wicked little viper. That's mean.
Good idea though.
What about putting it somewhere in the school's ventilation system?
[Edited by AdmiralThrawn, 1/12/2010 11:43:52 PM]
Looking at this from the eyes of those not yet pranked?
Pranks may be fun, but many of them are one way streets.
And anyway, work friends are called work friends because you're friends with them at work and then you go home. If you hang out with them otherwise, that's more than a little creepy.