When your society has inhabited a small, remote island for countless generations and boasts a population of only 300,000, the odds of having sex with a relative are significant. Luckily, Icelanders now have a handy tool to avoid family-sex.

Íslendingabók—meaning "book of Icelanders"—is an online incest avoidance search engine. Plug in your name and that of a potential mate, and the site searches a genealogical database to see how closely you're related.

Source & Full Story