Bikes that really ought to have an electric assist kit added to them.
http://fuckyeahweirdbikes.tumblr.com/post/47876848296/trecool-blog-donky-bike-bicicleta-de-carga
also here http://donkybike.com/
UK Postie from Pashley. http://www.pashley.co.uk/products/mailstar.html
also http://www.pashley.co.uk/products/courier.html