Just like asking for your astrology sign, in Japan, asking for your blood type is JUST as important (not that asking for your sign is any way important sweatdrop )

The Farmer Type A
calm, patient, sensitive, responsible, overcautious, stubborn, unable to relax
People with blood type A have a deep-rooted strength that helps them stay calm in a crisis when everyone else is panicking. However, they tend to avoid confrontation, and feel very uncomfortable around people. A types are shy and sometimes withdrawn. They seek harmony and are very polite, but all the same feel that they never really fit in with others. A types are very responsible. If there is a job to be done, they prefer to take care of it themselves. These people crave success and are perfectionists. They are also very creative, and the most artistic of all the blood types, most likely because of their sensitivity.

The Hunter Type B
individualist, dislike custom, strong, optimistic, creative, flexible, wild, unpredictable
People with blood type B are the most practical of the blood groups. They are specialists in what they do. When they start a project, they spend extra time understanding and trying to follow directions than others might. When they are doing something, all of their attention is focused on it. They tend to stick to a goal and follow it through to the end, even if it seems impossible. They tend to be less than cooperative, as they like to follow their own rules and their own ideas. They are individualists. B type people pay attention to their thoughts a little more than their feelings, and therefore can sometimes seem cold and serious.

The Humanist Type AB
cool, controlled, rational, sociable, popular, critical, sometimes standoffish, indecisive
People with blood type AB are hard to categorize. They can have characteristics on both ends of the spectrum at the same time. For instance, they are both shy and outgoing. They easily switch from one opposite to another. AB people are trustworthy and responsible, but can't handle it when too much is asked of them. They don't mind doing favors or helping out, as long as its on their own conditions. People with this blood type are interested in art and metaphysics.

The Warrior Type O
trendsetter, loyal, passionate, self-confident, independent, ambitious, vain, jealous
People with blood type O people are outgoing, energetic and social. They are the most flexible of the blood types. They easily start up projects but often have trouble following through because they give up easily. They are flighty and not too dependable. O types always say what's on their mind. They value the opinion of others and like to be the center of attention. Also, people with O blood are extremely self-confident.

Compatability by Blood Groups:
(Yes, not only can this fact help you when donating blood, but in your love life too! heart )
A is most compatible with A and AB
B is most compatible with B and AB
AB is most compatible with AB, B, A and O
O is most compatible with O and AB

Interesting facts:
A is most common in Japan (those silly perfectionist)
O is the concidered the best type
O is common in the United States (arrogant bastards)
AB is concided the worst type (Some companies actrually grouped their workers though blood types. Nobody wanted to work with the ABs)

Guess what! Chewibunny is not only born on Friday the 13th, the Last month of the year, but now has the worst blood type added to the list... Geez, ever feel like someone's out to get you? ^__^;;

(reffence is found all over the internet, and a few fact recalled from my head... Main descriptions were found of a site that took it from another site... yeah, I can't exactly give proper credit...)