Something you might have heard if you've ever visited London- or are sufficiently up on your useless trivia- is that the phrase 'Big Ben', commonly used when referring to the tower, actually only refers to the bell inside the tower. The tower is just called the Clock Tower.
Well, was, anyway. In commemoration of Queen Elizabeth's Diamond Jubilee, the tower is getting renamed Elizabeth Tower. Whether you want to keep calling it Big Ben is up to you, but overall, it's likely going to end up being decided by haphazard, disjointed public vote, much like the one currently underway with, depending on who you ask, either the Sears Tower or Willis Tower.
Please update your useless-trivia memory banks to reflect this.