Brrr! 
I love running in the cold though - very invigorating! I'll be plodding 3 miles or so tomorrow morning - I'll wait till it gets light first though 
That sounds like a good cause Que Sera.
If you decide you'd rather not have people shouting at you, don't wear your name on your vest - job done. I had "Screamy" on mine last time which people seemed to find rather amusing so I'll probably do that again. I imagine it must be pretty unwelcome being yelled at when you're going through a real bad patch though.
I never actually experienced that because a lady I'd been talking to on RW caught up with me and was struggling too, so we ran/walked/limped the second half of the race together - we were too busy chatting and enjoying ourselves to think about how far we had left to go. Also I think once I "let go" and forgot the time I was aiming for I just relaxed and got on with it.
Enjoying it is more important that anything else - there are plenty of other marathons where you can focus on your PB if it doesn't pan out on the day.
Edited: 18/10/2011 at 12:04