There's a reason the first thing I do with a new laptop is add about fifteen assorted stickers to it. Very helpful at conferences and such when it comes to keeping laptops distinct.

Exactly! Also: never clean the keyboard or wipe off any coffee or marmalade spills; that way the thief will probably decide they don't want it after all, hand it back and go looking for a shiny, well looked-after one...

I thought that ... So why isn't there a spare MacBook Pro laying around the security line?

Hey, a name game: MacRoulette. You put your laptop through security with a bunch of others and you grab a random one. Practice safe computing and always have a backup.

Bonus points for those who leave a note with their password between screen and keyboard!

That is a fair point, however, in that case, there would be a computer left over on the belt, that the author would've seen when he got out of the scanner.

On a side note: do people not keep their laptops in sleeves (even when in backpacks)?

Are you not required to remove laptops from sleeves while sending through the scanner?

No you don't. As a nomad I fly a lot, and I always leave my laptop in its waterproof bag.

As a settler that travels ocassionaly I am often required to open or even turn on my laptop at the security check.

Where is this? I'ma frequent flyer, and have never once been sled to open my laptop nor have I ever seen anyone asked to do so (outside a short period after 9/11)

Europe, mostly flying to/from Slovenia.

To/from UK I've been asked "back then" when the craze started; in the last 4 years, never once. Which is correct: they are not scanning the laptop but rather the bag which the laptop would obstruct. Once it's out it doesn't really matter how it's packaged.