http://www.ccmr.cornell.edu/ask/Clancy.htm

Here is a link that discusses this (and I'm thinking this woman can actually spell college, too )

Also, Animal Planet (or one of the cable discovery type channels) had a really good program on this some months back that talked about all of the cat's sensory abilities, eyes, smell - and that in many ways their sense of smell was more keen than a dog's...wish I could remember what it was called, it was really an interesting program.