I travel a lot! (both on air and ground, but primarily by air). I have been checking my laptop in for about the last six months. At first I was concerned, but then a friend recommended a product to me to make my air travels easier. I use StompSoft's Digital Vault
http://www.stompsoft.com/digital-vault.html to protect all of my files when my laptop is out of my possession. I'm glad she recommended it because I really knew that I should have installed something to protect my files and retain my privacy. If you take a laptop with you on vacation, you definitely should consider a product like this. Even if you do take your laptop on your flight, just think of how often you leave your laptop alone in the hotel room.