http://gwydir.demon.co.uk/jo/maze/simple/trispiral.gif
I quite like this one and the curiosity aroused could inspire a new chat-up line to a guy at the pool:
"Excuse me - I don't have my spectacles so do you mind standing still while I trace my finger around your bum to find the way out of there ?"
Also, for those who might want to customize with something special, there are plenty of ideas here:
http://commons.wikimedia.org/wiki/User:AnonMoos/Gallery