I know that post offices in the UK have used the single queue feeding multiple (hah!) cashiers like forever. It would work better if they were to observe the current queue length and put on more cashiers once it got to a certain size though!
However, the other queue doesn't always move faster. Often a quick bit of observation and thinking can get you in a faster queue. For instance, at security checkins at airports sometimes 1 queue is feeding two x-ray machines and another queue is feeding 1 x-ray machine. Obviously the two-machine-queue is likely to go through faster, but lots of people don't seem to notice and just join the queues randomly.
Of course, it probably only makes a difference of a minute or so, which is trivial in the grand scheme of things, but hey - we can take fun where we find it, eh?
Cheers
