Quoting Brian May (brian@microcomaustralia.com.au):
You might think you are protected by having all your files encrypted, then the foreign country demands you give them your decryption key, with threats of jail if you don't.
Schneier has had a number of articles about creative ideas to deal with that scenario. There are some very creative people out there, and I cannot remember most of the nuances. One was a filesystem that, if you give it one key gives access to the real data but if given a different key gives access to innocuous decoy data. I've also considered storing on any traveling laptopc some large files containing random data and publicising widely the fact that I do so.
I wouldn't take any sensitive information on computer/phone/tablet overseas, even encrypted, unless I absolutely had to.
Yes, it's an interesting problem. One possibility is to bring only a generically loaded machine with the intent of later wiping it upon reaching one's destination and downloading the intended substantive contents off an Internet repository established in advance for that purpose. The trick would be to keep the download size and transfer time reasonable.