I found this via retweets from Tim O’Reilly on Bio-Medicine.
The boy tracked down his father from his Y chromosome, which is passed from father to son unchanged. The gene variant patterns it carries can help trace the concerned paternal line, according to a report in New Scientist. All that it cost the boy to trace his father was $289 paid to FamilyTreeDNA.com for the service. In fact, his genetic father had never supplied his DNA to the site. For investigation, the site needed someone in the same paternal line to be on file. After nine months of waiting and making his contact details available to other clients, the boy was contacted by two men with Y chromosomes closely matching his own. These two were strangers, but the similarity between their Y chromosomes suggested there was a 50 per cent chance that all three had the same father, grandfather or great-grandfather.
Though the boy’s genetic father was anonymous, his mother knew the donor’s date and place of birth and his college degree. Using another online service, Omnitrace.com, he bought the names of all who had been born in the same place on the same day. Only one man had the surname he was looking for, and within 10 days he had made contact.