My personal law is "always doubt of any list with TEN items -- there's probably something missing or something extra". If we had 12 fingers, there would be 12 commandments... :)

An getting even more off-topic: do you know why some people cross the number 7 (for example, the Lucida Blackletter font: http://www.fontage.com/pages/lblack.html)? Because when Moses announced the seventh commandment, "You shall not commit adultery", everybody said "Cross the seven! Cross the seven!". (It's funnier in portuguese...)