Laptops are easily lost or stolen and in order to protect your emails, web passwords, encryption keys, etc., you should really think about encrypting (at least) your home directory.
If you happen to have
/home on a separate partition already (
/dev/hda5 in this example), then it's a really easy process:
Copy your home directory to a temporary directory on a different partition:
mkdir /homebackup cp -a /home/* /homebackup
Encrypt your home partition:
umount /home cryptsetup -h sha256 -c aes-cbc-essiv:sha256 -s 256 luksFormat /dev/hda5 cryptsetup luksOpen /dev/hda5 chome mkfs.ext3 -m 0 /dev/mapper/chome
Add this line to
chome /dev/hda5 none luks,timeout=30
Set the home partition to this in
/dev/mapper/chome /home ext3 nodev,nosuid,relatime 0 2
Copy your home data back into the encrypted partition:
mount /home cp -a /homebackup/* /home rm -rf /homebackup
That's it. Now to fully secure your laptop against theft, you should think about an encrypted backup strategy for your data...