Hi James. I saw your name as the newest member, and I thought that sounded ominous. Members here have suffered a spate of bike theft recently, so you're in good company, and there will be plenty of useful advice for you.
In the meantime, good luck with recovering your Brommie.
EDIT: Just looked at your blog. There's loads of Bromptons in central London, but I note that the green/grey colourscheme is pretty distinctive. Since it was stolen from EC, and I work in SE1, I'll keep an eye out for you.