Update (1/01/10): I hope you all had a good time last night. But not too good. To check the state of your gall-bladder, visualize a piece of toast dribbling with melted butter. If you instantly feel nauseous and clutch your right side, you have overindulged: you need to cut out all fat and alcohol from your diet for a while.

This is an actual test that was used by French doctors in the olden days. It should be revived: it does work. Try it!