I regularly drink 3 litres of water a day, more when its hot. It is 4pm here now and I have already drunk over 2.5 litres and a few cups of peppermint tea. I went out for a run at lunchtime and that always makes me thirsty in the afternoon. I really suffer if I don't drink enough water my body really seems to notice when it is a bit dehydrated (I'm sure that's why I get such killer hangovers).

Tlkiwi, I agree with you about the minging tasting water in London. I grew up in Scotland and tap water is lovely, it has no taste to it at all. When I moved to Preston all I could taste in the water was chlorine (or whatever other chemicals they've put in it), took me ages to be able to drink it. I buy bottled water if I'm in London, just can't stomach the water at all.