In the
Erskine Medical Library in Edinburgh uni one of the cubicles has grafitti on the bottom corner of the wall:

"If you're reading this, you're peeing on your shoes..."
( Fudgebags will wear you like a glove, Mon 3 Nov 2003, 16:25, archived)

My older brother used to glue pound coins to the bottom of toilets with the queens head facing up
Personally, What's quite funny, although not exactly graffiti, Is to write "reading this note will make you [insert insult her- eg.gay/smell/ugly]
(tom the astronaut, Mon 3 Nov 2003, 18:17, archived)

does glue work underwater?
how does it dry?
(chegosaurus sucks at b3ta, Mon 3 Nov 2003, 19:30, archived)

superglue uses
water molecules to initiate the polymerisation reaction for bonding, it doesn't 'dry' as such.

Er... I'll go now.
(Zak is pleased with your offerings, Wed 5 Nov 2003, 1:40, archived)

he's right
I do use... erm.. that.
( RarelyEvil, Wed 5 Nov 2003, 17:26, archived)