http://genome.cshlp.org/content/21/5/768.full
Family Tree DNA and others offer products that have statements like this associated with them:
"Matches are related within about the last 5 generations.*"
I'm not suggesting that what Family Tree DNA and others are doing is precisely what is described in the journal article. But they are probably, er, related.
Neat that once you have your data, you don't necessarily need to pay someone else to do the analysis. You could do it yourself, if you had someone particular in mind to compare yourself to. What Family Tree DNA and others offer is matching against everyone else they've tested and putting you in touch with each other if the match is close enough. It would be dating, only instead, it's finding genealogists who share chunks of ancestry. Which is pretty cool, if you are into that kind of thing.
