The Metropolitan Police in London have produced a clarification of the law surrounding photographing in public places, confirming that they do not have the power to stop people filming or photographing in public but they do have the power to stop you and view what you have shot. I applaud this and suggest those shooting in London print it off and keep it with them for when clarification is necessary The Details.
Update: The Metropolitan Police in London, yesterday updated their advice to the public on photographing in public places following a challenge by the NUJ......more.

August 9th, 2009 - 12:42 pm
A man has been arrested under the Section 44 of the Terrorism Act 2000 after taking pictures on Chatham High Street in Kent.
http://www.bjp-online.com/public/showPage.html?page=865334