These are very brief instructions on how to create an encrypted directory on an Ubuntu system. A usage scenario for this, is that you can keep your files encrypted while stored on a cloud storage service, and decrypt them on-demand only when necessary.
Install encfs:
sudo apt-get install encfs
Link encrypted and decrypted direcories:
encfs ~/.encrypted ~/visible
If the directories don't exist, encfs will ask to create them.
To umount:
fusermount -u ~/visible
To re-mount:
encfs ~/.encrypted ~/visible