London Eye at night. Queue of people, each with a camera with flash. Fill (or have representatives in) each pod. As first pod nears the end of the loop countdown and take near-simultaneous pictures. Next pod up sees flashes, counts to three and then does the same. So on to next pod, around to the beginning. Repeats when next pod nears the end. Continue for as long as queue lasts. Those outside will see a mexican wave of crackling flash bulbs, like a catherine wheel. Those inside the pods will view from close quarters.