theres also family tree dna

and the dna ancestry project

I understand something like one of these sites was used by UK police to narrow down a suspect (they submitted the DNA and received a close match by someone distantly related - which gave them the surname)

and I believe 15 year old who searched for his paternal fathers name
(he was adopted -the father anonymously donated sperm)
but he knew the University where his father went and so when he sent in his DNA test and got a surname - it was a matter of searching University attendance records ..