MacBook and Pro HDD vulnerability
Another small point on data security: the disks in the new unibody MacBooks and MacBook Pros are very easy to remove since they sit inside the new compartment housing the battery. It's a few seconds' work to whip out the drive and this is something that could happen to you, even if a thief leaves the computer. As always, the information on the drive is probably worth more to you than the computer itself. So this is another reason to use PGP whole disk encryption. A stolen HDD is absolutely useless if it is encrypted.