Blood types are useful things. They make sure you get the right stuff during a transfusion, but they can also supposedly reveal the inner workings of your personality and gauge your compatibility with others. 

Just like Godzilla and Gwen Stefani, blood types are big in Japan. Rock stars, politicians, video game characters - all of them list their blood type in their bios. Your blood type reveals your leadership abilities (which is important in the workplace and political office), lets others know who you're compatible with (which is important for your fans who daydream about meeting you) and who you're not compatible with (which is important if you want the characters in your party to kill the enemy and not each other).

There's no official scientific basis for blood type personalities, but they're fun to play around with. Here are some links to check out.

At Issendai.com, you can get a rundown of the personality for each blood type, along with the names of anime characters who share that particular blood type.

This article gives more background on the history of blood type personalities, along with personality profiles.

And last but not least, Wikipedia's take. Complete with profiles, lists of famous people with each blood type, and more historical/scientific information than you can shake a syringe at.

From what I understand, my blood type is B. B types are supposed to be excellent cooks. Well, I suppose my microwaving abilities are rather superior. I guess I love animals - at least, my cat and I have agreed to coexist in mildly cranky harmony - and I am forgetful. I once wrote with the wrong hand for five minutes back in elementary school because I forgot which was my right and which was my left. Carpal tunnel has made this easier - I write with the hand that hurts the most.

How do you all stack up against your blood type personality profile?