On a condom machine
in a pub in Winchester was lovingly inscribed:

'Insert baby for refund'
( doctordoctor hasn't annoyed a left-wing liberal since, Mon 3 Nov 2003, 13:46, archived)

On a broken condom machine in a pub
the landlord had put a sign on it "Out of order - please use withdrawal method"

Made me laugh.
( Farmfoodsman, Mon 3 Nov 2003, 14:22, archived)

On a different condom machine...
...in a different pub, I've seen written "don't buy this chewing gum, it tastes terrible".
(Illon Gruci, Mon 3 Nov 2003, 14:28, archived)

with thew obligatory reply;
'oh, but what bubbles ... '
( spiny is content., Mon 3 Nov 2003, 20:10, archived)

How about
"Homes for retired Semen. Please give generously."
( L-Space - scientia sapientes vocat., Tue 4 Nov 2003, 12:46, archived)

or
25¢ for recaps...
( Syncubus Yarr! Ye'll be walking Planck's Constant! [GMT-5], Tue 4 Nov 2003, 16:34, archived)