pbr The DVD and Blu-ray UK launch of James Cameron's 3D epic Avatar has been celebrated with the erection of a replica of Pandora's Tree of Souls in Hyde Park.br ppbr The tree, which is made of 20 miles of fibre-optic cables, allows visitors to connect their phones and iPods to the structure and send messages and pictures.br ppbr Avatar-star Stephen Lang attended the event on Sunday to meet fans and happily signed autographs and posed for pictures.br ppbr Since it's box office success, Avatar has continued to break records. On Monday, it sold a record 222,824 copies on its first day of release in the UK.br ppbr This beat the previous record holder, Christopher Nolan's The Dark Knight, selling more Blu-ray discs in its first 24 hours than the other one did in its first week.