Hey there!
Rigsby doesn't sound like an Icelandic word, but rather Scandinavian and would probably derive from Rig which could either be "government" or "rich". "by" would mean farm or town. It is therefore most probably a name of place, but last names in Scandinavia are very often based on the birthplace of some ancestor. In Iceland we don't even have last names as such.
Good luck with your further namehunting. IngaAusa (talk) 01:17, 6 August 2008 (UTC)