Turtle Power! '300' Loses Box-Office Battle To 'TMNT'

Two-time champ '300' slips to #2; 'Shooter,' 'The Last Mimzy' debut in top five.

Not Your Average Kiddie Flick: 'Last Mimzy' Invokes Buddhism, Genetic Code

'It's the quintessence of innocence,' director Robert Shaye says of science-fiction adventure.