I found this list of funny British laws in a news article.
1. It is illegal to die in the Houses of Parliament.
2. It is an act of treason to place a postage stamp bearing the British monarch upside-down.
3. In Liverpool, it is illegal for a woman to be topless except as a clerk in a tropical fish store.
4. Mince pies cannot be eaten on Christmas Day.
5. In Scotland, if someone knocks on your door and requires the use of your toilet, you must let them enter.
6. A pregnant woman can legally relieve herself anywhere she wants, including in a policeman's helmet.
7. The head of any dead whale found on the British coast automatically becomes the property of the king, and the tail of the queen.
8. It is illegal to avoid telling the tax man anything you do not want him to know, but legal not to tell him information you do not mind him knowing.
9. It is illegal to enter the Houses of Parliament in a suit of armour.
10. In the city of York it is legal to murder a Scotsman within the ancient city walls, but only if he is carrying a bow and arrow.