The flipper bridge JUN 14 2010
In Hong Kong, cars drive on the left while in the rest of China, they drive on the right. If you're building a bridge between the two, you've got to come up with a clever way to switch lanes without disruption or accident. Behold, the flipper:
The only way that could be more cool is if one of the lanes went into a tunnel under the water or corkscrewed over the other lane in a rollercoaster/Mario Kart fashion. Lots more on the NL Architects site.