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This is a BBC show that is run on Animal Planet every weekday morning at 8:30 a.m. It's like a Nanny 911 for pets. It may give you some sense of optimism that this problem can be solved with the services of a behavioral consultant. Barking Mad works with all of them--dogs, cats, ducks, geese, overly aggressive turtles and overly shy hampsters. Not all problems can be solved, nor will your cat necessarily become the pet you want him to be, but you could end up with something slightly less awful.
I'm already willing to bet that this has something to do with the cat's sense of his territory. Dogs are all about hierarchy; cats are all about real estate. Read a book called "the Tribe of Tiger" if you want to get some sense of why the cat brain is wired this way. Your cat may need his own "space," i.e., some sort of rearrangement of your apartment/house or the way you use it so that he feels there is some area that he can effectively protect from territorial incursion. It may well be that your living space is too small for him, in which case a farm may be the best answer, but you'll never know if you don't check it out.
For those of you who insist that cats can't be trained, actually, you can find any number of professional animal trainers who insist that cats are easier to train than dogs. The key is to understand that you have to make them want to do something; unlike dogs, they're never going to take orders from you just because you're the alpha male, because, again, they don't respond to hierarchy in that manner.