Thanks everyone! - I saw Richmond had a half too, I might give that a go in the Spring. Thanks for the clip paultom - that's how I remember it, the crowds were fantastic!
I've just signed up again for the Ealing half again. The website says the course will be changed slightly this year so hopefully my time will get faster! I'm doing Brighton half for the first time too, so it will be interesting to compare the two. Is there another half in London?