An obscure art-house movie called The Dark Knight,
starring a pair of little-known actors named Christian Bale and Heath Ledger,
arrives on DVD and Blu-ray today. Also debuting on DVD this week: The animated
blockbuster Horton Hears a Who!, starring Jim Carrey as the titular elephant
with microscopic friends; and Man on Wire, James Marsh's riveting documentary about acrobat
Philippe Petit's 1974 attempt to perform a high-wire act between the World
Trade Center's twin towers.