Oh man I have a book all about silly things like this. Several sections are devoted entirely to silly laws that still exist. Lemme get it right quick.
It is legal...
-in parts of Pakistan, for a man to swap his sister for a wife
-in Alaska, to shoot a bear, but not to disturb it's hibernation by waking it up.
-in Nevada, to hang anyone who shoots your dog on your property.
-in Utah, to marry your cousin, but only if you're over 50.
-in England, to shoot a Scotsman, but only if you do so in Cathedral Close, York, on any day but Sunday.
-to have sex in Florida, but only in the missionary position.
-in Sweden, to be a prostitute, but not for a man to use her services.
-in England, to shoot a Welshman, but only if you do so with a bow and arrow inside Chester city walls after midnight, or with a longbow in Hereford on a Sunday.
-for saleswomen in Liverpool to go topless, but only in stores selling tropical fish.
-in Pennsylvania, to use the same vehicle to deliver carry-out food and dead bodies.
-for a burglar in Michigan to sue a homeowner for any injuries sustained while burgling their house.
-to have sex in Virginia, but only in the missionary position AND with all the lights turned off.
-to snore in Massachusetts, but only if all the bedroom windows are closed and locked (duck and cover, Jeph.)
-in Iowa, for a man to kiss a woman, but not for more than five minutes, and not if he has a mustache.
-in Paraguay, to fight a duel, but only if both parties are registered blood donors.
-in Britain, for a man to urinate in public, but only on the rear wheel of his motor vehicle, and only if he's touching the vehicle with his right hand.
More some other time, probably. If they go over well.
EDIT: all of the above are quotes from a book entitled "Take Me To Your Leader." take up any discrepancies/unpleasantries with the dude who wrote it.