I loved Sasha Borovik's blog entry entitled
Psychophysiology of Blackboard Teaching . Using Blackboards is really important to the way the mathematics is transmitted from person to person. I especially loved the pictures of teachers carrying blackboards across an arrid landscape, from Samira Makhmalbaf film Takhté siah "The Blackboard".
(Internet Movie Database). Hopefully the new Mathematics Building at the University of Manchester will have a large selection of excellent blackboards and manchester mathematicians will not have to travel around campus thus equipped!