There are literally thousands of free open data sets for the UK, with which you can do some pretty awesome things. Or if you're interested in just London, then there's a another load of localised sets. 

A quick search on here, plus an hour or two of munging and crunching, means you might never have to take a newspaper at its word again. Looking to open a shop, check where the best footfall, least crime is. Fast food chain? Check out obesity rates across the UK.