[Hampshire] Securing a laptop against theft

Hi all,
After a friend has had his full spec macbook pro 15" stolen from his
house, I'm considering beefing up my laptop security.
My initial thoughts are to encrypt /home,/tmp and swapspace. But to
ideally that when the computer is locked (gnome) then the volume is
re-encrypted until it's locked.
The other side of the security I suppose would be tracking the laptop
whilst stolen.

Any thoughts?