Here comes an odd little low-practical question out of curiosity:
What does the review counter show? The little counter in the upper bar is always showing a high number (fluctuating a bit) even when review queues are empty. I might have missed an explanation somewhere when being sworn in with the review privilege.
It could of course just be because there are more queues than I am allowed to review at my place in the hierarky (odd that I would see a tempting counter in that case), but there don't seem to be any queues hidden from me.