Markus and David -- a great blog, as always. I cannot help but to want to add to the blog by making a point on the art of purposeful visualization. Edward Tufte's work is legendary in this field -- http://www.edwardtufte.com/tufte/ -- and his one-day course is envy-inducing for its power in showing the beauty (and ugliness and consequences) of good and bad visualisations. I'd even go as far as saying that visual explanations are essential in short presentations. A picture tells so much more than a thousand words; it can either skew, manipulate, obscure, or illuminate, explain or enhance in ways that words probably can't. (Edward's not family and I don't have shares in his in-house publication house, but I am a serious fan of his work).