Icelandic: Prepare for a Headache
As far as most visitors are concerned, there are two important points to know about Icelandic: (a) it's one of the world's most difficult languages to master, and (b) almost everyone in Iceland speaks superb English. So unless you're here for the long haul, there's not much reason to even try. I contented myself with the ability to semi-correctly pronounce Icelandic: a steep enough task even with 91 days to practice.