How much of your identity is formed by the routines and details of your life? What is essentially you? When you're done mulling over the implications of Jodie Foster switching bodies with her mom and George Burns stubbornly wedged into a teen, here are a few more leads to help you explore the idea of flexible identity.

Being John Malkovich (1999)-Through a tiny door behind a file cabinet, characters motivated by ennui, unrequited desire, or good old-fashioned lust enter and eventually seize control of poor Mr. Malkovich's body. I'm still amazed this film made it to theaters with its strikingly fluid view of sexuality and bizarre premise intact.

Prelude to a Kiss (1992)-If you can ignore the disturbing idea of Alec Baldwin and/or Meg Ryan doing anything, anywhere, at anytime, alone or together, alive or dead, you're left with an interesting question: Could you tell if your "soulmate's" soul was switched with another?

Trading Places (1983)-This 17-year-old comedy has lost none of its charm, thanks equally to Eddie Murphy and Dan Aykroyd. Identities, in this case, swap not through supernatural means, but through the manipulations of two rich old farts and their malicious experiment in nature vs. nurture.

Dark City (1998)-The populace of an indeterminate time and place unknowingly undergo an experiment to see if the human soul is more than the sum of memories. Kiefer Sutherland's mad scientist affectations are a painful but small price to pay for this beautiful sci-fi movie from Alex Proyas, director of The Crow.