Six degrees of separation--Sometimes fewer

There is a big article on the idea here, but I am concerned with the mundane practical applications. The idea is that any two people on the planet can be connected by people they know: For instance, I am one step away from people I know and two steps away from people who are known by people I know. Everyone on the planet is at most 6 steps apart.

There are things about the theory which I am curious about: Do we count as people we know only the ones we are currently in contact with? I must have known on the order of a couple of hundred Marines (on a first-name basis) over the 11 years in that organization, but it has been a long time and currently have only one phone # that I think is valid. Also, when research is done, it must be very difficult for subjects to name every person they know, but even if you could do that you would have to have similar data on each of those people and so on. So what I am getting at is this: If I wanted to say hi to a bushman in the Kalahari, how would I know who to pass the message to first?

This whole line of musing comes from the nomination of Sarah Palin. I looked-up some of her stats when I got the news of her being picked by McCain for VP. She attended the University of Idaho at the same time I was 8 miles away attending Washington State University. At the time, the drinking age was 18 in Idaho and 21 in Washington, so all the college bars were in Moscow and kids from both schools mixed freely.

There is a near-certain connection that I know of. I was pals with a girl who had just graduated from UI when we were working in Sun Valley and she was a Journalism major, just like Sarah Palin! Those two must have met since they had the same major and graduated the same year from the same smallish university. The problem as above with the Marines--I have no idea where she is now. We exchanged the odd letter for a couple of years after we both left Sun Valley and then lost touch.