Apropos same ...
If I had a laptop to travel with, I never would, given the rather less than sacrosanct treatment of one's data, especially when crossing international borders.
However, I have a great screen saver which is guaranteed to freak out any Nosy Parker who is wont to check out what you're doing on your computer:
At a click it starts a visual countdown from 10 (virtually full-screen font). If you start mumbling gibberish or, even better, some form of Arabic, you're guaranteed to cause an effect.
I particularly enjoy capping off the countdown with an elegant calligraphic rendition of "Allahu akbar".
(You could also offer your seatmate a 72-hour Depend®.)
