Secure keyboard input

Any really sensitive file in the user's home directory should be protected by account permissions so that non-root users wouldn't be able to modify, or even read, them. In addition, a number of distros already have the ability to encrpyt some or all of the user's home directory, so that casual observers can't read the files. I think the previous poster has an excellent point, though: if you don't have a foolproof way of getting back to a login prompt, you can't say much about any sort of password-based security, including encrpyted home directories.