Dutch designer Stani Michiels won a contest by the Dutch Ministry of Finance, the goal of which was to design the new 5 euro commemorative coin with the theme 'Netherlands and Architecture'. He explains both the creative and technical process in great detail on his website. An interesting detail: he used only open source software for this project: Python, the Gimp, Inkscape and Phatch (a photo batch processor).

Oh, and before you ask: no, we don't print money