An article caught my eye today entitled:
How to Defeat Full-Disk Encryption in One Minute
When you read this, it's a clever idea. Someone basically wrote a boot sector virus that sniffs hard disk encryption passwords and saves the password for later retrieval. This attack certainly isn't anything new, I'm not sure if anyone has written an easily consumable utility for it before now though.
If you're worried about keeping the data on your laptop secure (who isn't), it's not just about encrypting your hard drive. It's probably a good idea to use a bios boot password and keeping your laptop physically secure. If you're traveling, don't leave it lay on a desk in plain sight. When you're not using it, put it away in a bag. Make sure you lock your doors. When the machine is powered on, don't walk away even for a minute without locking the screen.
If someone wants to target you specifically, they'll likely get what they want eventually (unless you catch them at some point). The trick to sane security measures isn't to stop people like that, the goal is to make sure that a random attacker is going to pass you up in favor of someone who is more lax about security. This is comparable to locking the door to your house. If someone wants to get in, they can, but the lock can help persuade the bad guys to go look for an unlocked door.