When I stop at traffic lights, I will often put the bike in neutral and put both feet down, as it is more comfortable than sitting with one leg up. There are a LOT of traffic lights in London!
Also it means if a sudden gust of wind happens I don't get pushed over. I am also a proponent of the "Hendon Shuffle".
This is a good read.....
http://www.survivalskills.co.uk/riding_skills_43.htmEdit. DSA is Driving Standards Agency (government department)
IAM is Institute of Advanced Motorcyclist