OT and nitpicking but the part about Icelandic names is actually slightly incorrect. The typical Icelandic "surname" is made up of the genitive case of the father's name (in rare cases the mother's) followed by "son" or "dóttir", not "sson" or sdóttir". It just so happens that the genitive case of most names ends with an "s", e.g. Gunnar->Gunnars or Guðmundur->Guðmunds. There are however many names where this is not the case. My name for instance, "Örn", is "Arnar" in genitive case and thus if I had a son his surname would be "Arnarson" and my daughter's surname would be "Arnardóttir".