I have been using an encrypted home partition on my Asus notebook for about the last 14 months using loop-aes. It has always worked well, initially under Debian and now under Gentoo. There are good instructions for setting everything up in the loop-aes readme. There is also a good Debian based howto, but I can't recall the address off-hand. For practical purposes the machine boots into a terminal and I log in as root to mount my home partition. I then log-out, log back in to my user account and run startx. To mount the partition successfully requires both the key (which you can keep on the disk or for additional security on, say, a usb stick) and a passphrase.
The options for encrypted file systems have apparently improved since I set this up, but I haven't investigated any further. Good luck. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
