There are very few entertainment options in London which are free and, at the same time, really interesting. And which also have the &lsquoI was there&rsquo stamp. Portobello in Notting Hill before it gets dark is a favourite, the Changing of the Guard at Buckingham Palace is okay once in a lifetime but otherwise over-rated, and the musicians all over, especially at Covent Garden Square during the day, are top of the line. Diwali in Trafalgar Square is a recent addition, and so are the &lsquoLondon Free&rsquo weekends in September. Some idiots burnt down the Cutty Sark in Greenwich, sadly, and it is no fun to go and look at a cremated hull. But it has to be Speaker&rsquos Corner in Hyde Park which tops the list.