Science fiction greeting used in multiple bad B-movies from the 50's and 60's, and constantly ridiculed by the members of Mystery Science Theater. Also spelt "Nanuu-nanuu". My friends have actually started greeting people like this. Everyone thinks they're on crack, it's awesome.

Said by Robin Williams as Mork from Mork and Mindy. This was at the end of the show when he was talking to the mother ship I think. At the same time he twisted his ear a couple times. This is all fuzzy but I will be happy to update it correctly if you /msg me.