I vaguely remember London Bridge being sold to an American when I was a child and later we would joke that he had really wanted to buy Tower Bridge, but ended up getting the wrong one, which of course wasn't true.
I had never heard of Lake Havasu either, until watching the film 'Falling Down' where Robert Duvall's cop character was hoping to retire there and I remember wondering whether the Lake Havasu in the film was a bit of sarcastic jibe against the place. Well, now I know, and in this fine article from the BBC, the entire story of how London Bridge ended up in the Arizona desert is told, with Robert Paxton McCulloch emerging as a man with very big ideas that paid off.