Another of my faves, when talking about something immeasurable or un-debatable, is to say, "How long is a piece of string?"

I have heard people say, of a pregnant woman, "She's as big as a house!" but this seems vaguely unsatisfactory to me, since houses come in all shapes and sizes and some are actually quite little. Maybe they should say, "She's as big as a bread oven!" - since she's obviously got at least a bun in it!

Let us go in peace to love and serve the board.