Nap, zizz, siesta… Simon Williams, author of The Politics of Sleep, wrote in this space a few weeks ago of the benefits of a short daytime snooze, but he didn't say where you could do it. Some can sleep upright in a chair, men particularly; many of us really need to slump – but where? I have slept – I must be careful how I phrase this – in some pretty odd places, such as an out-of-sight sofa in a club or a hard park bench; when the Observer was based in Blackfriars we could sleep on cushions and costumes in the photographic cupboard: girls delivering fashion would be startled by a head rearing up from within like a walrus disturbed on a rock. The Royal Society of Medicine once had a whole day's conference on sleep, extolling the joys of multiphasic sleep – ie many snoozes, not just one long night – but again without any mention of where it might actually happen. I did learn some interesting facts, though: how long you sleep varies with size. If you're tiny you daren't sleep too long or something will eat you, while an elephant can safely doze for days. I'd like to see sleepers on daytime trains and a couch in every ladies' room; some hope. Perhaps I'll have I'll have to learn to sleep like a horse – standing up.