I found this interesting article at
The Committee for Skeptical Inquiry (CSI). I found it pretty interesting. I have copied and pasted most of the article below.
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Black Cats
The cat was worshipped in Egypt and to kill one was considered a capital crime. When an Egyptian family's cat died, the cat was mummified and the family went into mourning. Romans, also, considered the cat sacred and introduced it into Europe. By the 17th Century, however, the cat began to be associated with witchcraft and it's luck turned from good to bad in many areas. A practice that became popular for a time was to burn cats and other animals on Shrove Tuesday (before the start of Lent), in order to protect one's home from fire and other calamities.
Superstitions centering around the black cat are some of the most well-known and popular superstitions today. It is interesting, though, because the good or bad luck they possess is dependent on where you live in the world. In Britain and Japan, having a black cat cross your path, is considered good luck, whereas if you live in the USA or several European countries, it is bad luck to have a black cat walk by.
Good luck associated with black cats include:
Possessing a black cat.
Having a black cat greet you at a door.
Having a black cat enter your home.
Meeting three black cats in succession.
Touching a black cat.
Bad luck associated with black cats include:
Meeting a black cat early in the morning.
Having a black cat turn its back on you.
Scaring or driving away a black cat from your property.
Walking under a ladder after a black cat has walked underneath it.
Onyx 
