hi mattes,
take
bcrypt from the core to encrypt files or tgz-packages,
encfs to encrypt whole directories,
cryptsetup to encrypt whole partitions,
pwsafe to encrypt and store your passwords,
enigmail to encrypt you mails with a stable gnupg-package (did you know about security flaws in this version?),
sshfs-fuse to get a secure-mounted filesystem from a ssh-server.
i think there are various ways to secure your digital life ;-)