Jurisdiction

Hi everyone,

I have a question about U.S. law.

Generally speaking, it's wise for Japanese people to avoid U.S. 
jurisdiction, because of e.g.:
  - VERY EXPENSIVE damages
  - punitive damages (we have no punitive damages)
  - fact-finding of juries which is difficult for us to foresee (we have 
no juries; in Japan judges find not only law, but also facts)
  - decisions of juries also about damages
  - higher risk of liability.

Other problems:
  - another language
  - innocence of U.S. law and 50 State laws.
  - another legal culture (Japanese law is continental civil law).

Then, what do you think of the possibility that the U.S. courts affirm 
their own (international) jurisdiction, especially about following cases 
related to Japanese wikipedia, considering that our servers are situated 
in California?

1. a person living in Japan sues a person living in Japan.
2. a person living in U.S. sues a person living in Japan.
3. a person living in another land sues a person living in Japan.
4. a person living in Japan sues a person living in U.S.
5. a person living in U.S. sues a person living in U.S.
6. a person living in another land sues a person living in U.S.
7. a person living in Japan sues a person living in another land.
8. a person living in U.S. sues a person living in another land.
9. a person living in another land sues a person living in another land.

Or, is it to decide not by the actual address, but by the domicile of 
the person?
Is the nationality of the person relevant?
Is it easy in U.S. to exclude the U.S. jurisdiction by agreement of 
parties? If so, what are the requirements?

Thanks,

T. Nakamura