A large Half-Blood Prince IMAX poster, spanning about 13 metres by 10 metres, is being given away in a competition set up by the National Media Museum.  The contest will run until August 3, 2009. The winning poster must be picked up at the museum, in London, and the winner must pay for their own travel. To participate,  email the answer to the following question:

Which of these Harry Potter characters is the largest?

1. Hermione
2. Hagrid
3. Horace Slughorn

Thanks SS