When driving back from a Workshop with the ART group of Fraunhofer IAIS at Naafs Häuschen I saw some interesting posters. 
A new car-related portal for selling and buying cars (pkw.de) has an interesting advertising campaign out. The only argument is on an easy to use and quick user interface – nothing else. So far many of them have tried to argue with the largest set of offers, but recently many of the major players (mobile.de and autoscout24.de) have improved their user interfaces.
It seems that a broader awareness for the user interface – basically that you sell based on your user interface – has finally arrived in Germany, too.
I really like these designs for single-purpose mathematical machines – I have a cylindrical Otis King multiplying/divinsion calculator that has always fascinated me.
(like this one: http://www.svpal.org/~dickel/OK/OtisKing.html)
It’s nice to think about how the physical shape of an object both allows and (maybe more importantly) constrains the actions you can perform on/with it, in such a way that the mathematical „program“ is encapsulated in a physical form.