A:  Actually, a browse through the Pitbull Wiki site gives some idea... This is what I've found, as to where Pitbulls are not legal to have, or are in the process of becoming banned or strictly regulated: 

ACTIVE BANS

Miami, Dade County.
Delta, Utah
Springville, Utah
Independence, Missouri
Springfield, Missouri
Council Bluffs, Iowa
Royal City, Washington
Denver, Colorado
Prince George's County, Maryland
Yonkers, NY
Garfield Heights, Ohio
Sparta, Tennessee
Melvindale, Michigan



PROPOSED:

Oklahoma
Shelbyville, Tennessee
New York City, NY
Aurora, Colorado
Youngstown, Ohio
Richland, Washington
Tupelo, Mississippi
Parker, Colorado
Chicago, Illinois

In the UK/England, Ontario Canada, Pitbulls are banned and not legal to own.

Q: What is all this about bloodlines and game testing?

A: Back in the days when dogfighting was legal and socially acceptable, dogmen would "test" their dogs in the ring against others. Testing for "gameness" would help them decide if a dog was able to keep going in any circumstance, no matter of exhaustion or pain. These days, this would also apply to weightpull, springpole, any other work or competition. This is what the pitbull what bred for, characteristic to keep going no matter what!
So it's really no surprise that bloodline can be a factor, when it comes to a dog's performance. If it's parents were very good at what they did, they would pass their traits and likely the offspring would be very successful as well. Two champion weight-pullers could very likely produce champion pups.

Some breeders have continued lines of the original pitbulls bred for fighting. Or tried their best to keep the lines true to what they were years ago. These are perhaps some of the best representation of the breed today, since they haven't changed much since the breed's creation.
Want to know more about Fighting Pitbulls?? I will not cover it here, so check out these documentaries:
    

Q: Are Pit bulls good family pets?

A: This is a tough one, and all really a matter of the person wanting to bring one home. I will not say that a Pitbull is right for everyone. There are several things you have to take into consideration before ever thinking about bringing home a dog. Much more, if you are wanting a pitbull. But I WILL say, that everyone who brings home one of these loving, loyal dogs, falls in love quick and won't give up their best friend for anything!

First I will mention that a Pit bull is a bit different than a Golden Retriever, due what it was bred to do. A Pitbull is very prone to dog aggression, and very high prey drive. So if you have other pets, you owe it to yourself and them to do your research. For a new Pitbull puppy, it is very important to keep his first contacts with other dogs, very pleasant. I would suggest play dates with other puppies or older dogs that are very gentle. A negative experience with another dog, can mean bad temperament with most other dogs for the rest of his life.
In any case, you should never leave a pitbull with any other dog unsupervised, as even a very good tempered pitbull cannot be trusted to not start a fight.  A pitbull may not start the fight, but will always finish one!
I will also mention from personal experience, that you will want to invest in a strong leash and collar. I have gone through several that I thought would be efficient, but they do break. A dog breaking free from you while walking could mean disaster!
If you are looking for a great family pet that loves to play, loves children and cuddling, a pitbull puppy could be just what you need! It is not recommended to ever leave any pet unsupervised with children, however.
Any kind of human aggression, is bad representation of the breed, and is not to be tolerated.  

Q: Would a pitbull make a good guard dog?

A:  Probably not.. To put it this way, a lot of pitbull owners would probably say that if a burglar were to bring good enough of a treat, they could steal everything in the house including the dog!
Although, that is not to say that a pitbull would not make an awesome watch dog. Most have the natural urge to bark up a storm if they hear someone getting close to their property. Probably not the best apartment-dweller, but I and several others are proof that it can be done, with understanding neighbors.
Due to the publicity that the pitbull has gotten throughout the years, most people will keep away from your home just knowing you have a pitbull. If that is not enough of a deterrent, the powerful barking on the other side of the door will definitely keep unwanted strangers away, and freak out the mailman.

Q: Where can I find one?

Now, if you are still wanting to find yourself a pitbull, the first place to check is your local animal shelter or pitbull rescue. It is also very important to ask about any breed-specific-legislation in your area to make sure it's legal to own a pitbull, or what requirements there are to owning one. A pitbull rescue will be very helpful in helping match you up with the perfect dog for your family and answering any questions you may have about the breed. If you do have other pets, make sure you arrange a meeting for them on neutral territory before bringing the new pitbull home.

If you insist on getting your Pitbull from a breeder, check them out thoroughly. Ask about the parents' health-testing and accomplishments. As for accomplishments, this is what determines a good representation of the breed, and whether a dog should be bred or not. If you find a breeder with no accomplishments in agility, conformation, weightpull, etc.. And no health testing, what so ever, get out of there!! This is a backyard breeder, and they are not interested in the well-being of this breed. They are looking for a quick buck, and it's likely you will later end up having to cover huge vet bills, and deteriorating genetic problems such as bad hips, or worse.