It's really simple to do. First install encfs
Create an empty folder where you want to mount your encrypted files.
sudo apt-get install encfs
Create an encfs encrypted disk in the Ubuntu One folder and mount it (giving it a name starting with a dot makes it invisible so it doesn't display in the file browser...not for security reasons).
mkdir -p ~/MySecretFiles
If you now create or copy files to ~/MySecretFiles/ they will be encrypted in Ubuntu One/.MySecretFiles, and you'll see messages about Ubuntu One uploading strange files like fhBPbcQvx79w39j1U2KKwhrC
cd ~/Ubuntu\ One
encfs ~/Ubuntu\ One/.MySecretFiles ~/MySecretFiles
To unmount it simply run:
The ~ is shorthand for /home/YOU, and you can of course name your encfs volume anything you want other than MySecretFiles.
fusermount -u ~/MySecretFiles
I've made a simple script for mounting and unmounting, saving me to remember all these commands. It looks like this:
Call it something you like and make it executable "chmod a+x scripname", and copy it to /usr/local/bin. That way it will be in path. Then mount it, and add an empty file to your share called .mounted
if [ -f /home/ragtag/Projects/.mounted ]
fusermount -u /home/ragtag/Projects
encfs /home/ragtag/Ubuntu\ One/.projects /home/ragnar/Projects
It's a simple hack the script uses to detect if it should unmount or mount your encfs disk (yes there is probably a better and more proper way to do this, but it works).