Nod to Jason Kotke and Kotke.org for this.
The Flipper Bridge
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.
Dave's blog 