I was wondering what the sign Mork made when he said "Nanu Nanu?" can anyone remember?

He would twist his ears.

Also, when he met someone new he would do this split handshake thing and say, "Na-nu, na-nu" This one website has the page from the M&M Scrapbook that shows how to do the Orkan Handshake. It's funny that it says hold for at least 4 seconds and no longer than 2 days.

http://hemsidor.torget.se/users/s/swes/mork/handsh.htm