How do I find a vanished bizz partner

[Naughty]

This is the case: I was starting of a small partnership with somebody who needed design stuff done. I designed, he promotes. He does that very well as far as I know. But before we started, he kind of vanished.

Now, in this case I am not afraid I got stabbed in the back, as I did not invest anything other than some hours for design at this point.
This guy was a long term client of us, so I just want to check if he actually is okay. He is a street racer and something 'might' have gone wrong there, who knows.

I want to find out where he's at, as I still have access to his FTP servers and all, so it is not that he is shut down, just gone with the wind.

For weeks on end I emailed and ICQ-ed him, but now I want to know if it is still worth it, lol.


Where do I start? I cannot call his name on boards, he doesn't like that.