Thanks for the responses guys.
I've been here for two nights now and it's been absolutley terrible weather. Quite cold for the south and really, really overcast. When we were descending at Heathrow the altimeter on the screen said about 250 metres before we got through the cloud. Oh well, I've still got a fair bit of time and the bonus of watching Sky at Night on TV, and getting Astronomy Now and Sky at Night a fair bit earlier
.
Thanks again.