Some are finding this feature is gone with the newer versions. As this is well discussed I'll keep it short. Use the app manager and look for the move button. It may not show if it's not supported.
Bob
How do i transfer movie from my internal memory to the external sd card? I can find the movies on the play movie icon, but i can not find it anywhere in my files.
Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic