Thanks Matthew,
Just to check I'm understanding the link, there's no way to secure OSX, such that you need to have an account under OSX to access the data? Rather you have to password protect the computer?
I guess I'm concerned that if my laptop is stolen, and someone takes out the HDD, and sticks it in another computer, then they have full access to my data?
If this is the case, I guess I'll have to resort to third party encryption tools (truecrypt) to keep my data secure.
Thanks.