As you will no doubt have seen everywhere, there is to be an official festival of Doctor Who the weekend of November 13 – 15 November. It’s in London at the Excel. If you haven’t been to the Excel it’s impressive as a convention venue – I went to the world science fiction convention last August and was very impressed. [Update 2016 – this has been and gone; the link doesn’t work]
Details of the festival on the official site include chances to meet the cast, look at props, meet writers and everything else. It’s not cheap; ignoring travel a single day for an adult and child is £100 plus booking fee. For this you get a Dalek or Cyberman ticket (same schedule, different order). If you stump up £160 plus booking you get TARDIS tickets meaning a free T-shirt, better seats and so forth (Friday already sold out). Not cheap, sadly.