As the guy who spends too much time near Urban Legends, a good chunk of them aren't true.
<a target=new href="http://www.snopes2.com/disney/films/finland.htm
">Donald Duck for example</a>
The duck's quack is one of the most commonly heard at snopes
The ferret one IS true, I believe it's called dysplastic anemia or something similar. I believe it is only life threatening the FIRST time she goes into heat though.
The 2 x 4, quicksand and rule of thumb have already been covered.
A raisin will do that in just about any highly carbonated beverage. A rock will fall if dropped, but it doesn't quite make the list.
bats turning left I believe is true,
Charlie Chaplin I know is.
I'd hit more of them but it's time to leave work