I love the way the advise gets more practical the longer the thread. This seems to be a universal law: jokey - practical - arguments - madness.
Just to reply to a few:
I've lost a few lb in the last couple of months and only want to lose about another 7lb (am trying). I agree that I can cope with only 2 travel chess sets and have removed one. I have one spanner to remove the wheels as last time I tried with the multitool it snapped. Can't remember what the other small spanner is for. Can't leave clothes at work for various reasons but have removed the fluff. Will remove one spare tube after checking that the remaining one is whole (or holeless) and ditch the spare puncture repair kit. Bungee is for holding the panniers in place so need that but can make do without the waterproof coat some days. I don't take my heavy U Lock some days and have replaced it with a nearly useless but light lock when the bike is going to be in a fairly secure place.
Tried to sign up for the next manned lunar mission but I'll probably be dead by the time they get round to it and I'm too heavy to reach escape velocity by flapping my arms (I've tried). In the spitit of handy tips though I've had a pee and trimmed my nails. Will replace heavy watch with girls one soon.
Thanks for all your help and advise, I'm feeling a lot better today