Hi Christian, thanks for letting us know about that; looks like everyone forgot that the theme Hay prepared for us (even himself included) is not usable for mobile devices (in any case, Hay - kudos for the work you put into this theme ;-).
As a temporary measure, I installed a mobile plugin (WPtouch) at the wikilovesmonuments.org website - if anybody feels like doing so, I'd appreciate some feedback on how the plugin works for you, if you like the design & colours (there are several possibilities to choose from), etc.
For the time being, the plugin forces mobile devices to redirect to http://wikilovesmonuments.org/contest, but we're going to set up a /mobile site which would contain all the information needed for users browsing with a mobile device or coming from the mobile application.
Thanks