Things of a phallological nature.
Someone using Dutch Google hit my site after searching for what means "penis" in icelandic?. Well, I'm no expert in languages, but according to Insult Monger the Icelandic word for penis is tittlingur.
Another place to look for foreign language insults and cuss-words is the Recommended Slang Links Portal.
Afterwards, (to cleanse the palate, so to speak) may I suggest you visit the Icelandic Phallological Museum, which is a museum filled with many different kinds of penises.