Can you put passwords on messages and pictures on your iphone 4s?

Can you put passwords on messages and pictures on your iphone 4s?

Not through iOS7, but you can jailbreak it using this video to walk you through the steps.

No. IPhone is designed for one user, so putting passwords on individual messages or pictures serves no purpose, since the owner of the phone has access to everything, and everyone else has no access to anything.