Geektastic: How about storing the stuff you don't want them to see on your personal cloud etc and sauntering through customs with a 'clean' laptop?
And did Apple not recently encrypt iPhones to the point where they do not themselves have the key to decrypt? I imagine Customs would struggle with that one if you refused to cooperate. How about File Vault whole disk encryption on a Macbook? I don't know the technical in and out but I imagine that would take customs a long while to hack by brute force - way beyond the cost that is reasonable unless you are convinced the laptop contains terrorist attack plans or something I am sure.
If you set your iPhone right, you can have it wipe the phone if the PIN is entered incorrectly too often as well!
That's the irony: any serious criminal with incriminating information is going to do exactly that. This policy will assist in catching little fish at best.
In regards to iPhones: bear in mind you have to use the more secure lock settings introduced in iOS8 to get the most benefit. The less secure settings from iOS7 and earlier do not encrypt everything on the device.