How to encrypt your home directory --

If you are using 10.x or above, be sure to check mark this feature when you install Ubuntu. This is by far the easiest solution.

If you need to encrypt it manually, either because you didn't enable this feature when installing Ubuntu, or because you have an older release that does not offer this feature as an install option --

Follow the directions at Dustin Kirkland's blog called "From the Canyon Edge" for the entry dated June 3, 2009. (I'm not allowed to post the URL here so you can google for it using the details I've provided.)

Be very careful to backup your $HOME directory prior to following those instructions. Also enter proper punctuation on all the line commands given (preferably Copy and Paste them to assure 100% accuracy).

I followed these instructions on three Ubuntu 10.x computers and it worked on all of them, though I did need to rebuild my Ubuntu "panel" (top-most task bar) afterwards.