To family historians — who've been inundated lately with genetic genealogy tools — the birth of another DNA Web site might not seem like news. Especially when the site is an offspring of the Sorensons: The family's backing has already spawned the nonprofit Sorenson Molecular Genealogy Foundation (SMGF) <www.smgf.org> — whose free database contains 70,000 DNA samples tied to participants' family trees-and Sorenson Genomics, the lab that provides testing services for Ancestry.com <dna.ancestry.com>.

So what's different about GeneTree <www.genetree.com>? The Sorensons' latest venture integrates DNA testing with another hot family history trend: social networking. GeneTree draws on Sorenson Genomics' testing services, information in SMGF's database and sister company Sorenson Media's Web technology to create a tool ABC's "Nightline" described as a "DNA Facebook" (referring to the popular <www.facebook.com>).