Being able to hand off keys harmlessly when some border control officer wants to turn your electronics inside out: Priceless.
Yup. This can be achieved quite simply without anything exotic, though. Tar your truly secret plaintext all up, and encrypt it with a header-less symmetric algorithm, to create a ciphertext. Store that ciphertext on a USB key. Create a decoy tarball, and XOR it with the ciphertext, essentially using the ciphertext as a one-time pad, and store the result on your laptop. When asked what these random encrypted files are, you XOR them together to produce the decoy. Simply deny that there is a passphrase involved at all. For clueless border control, this would be sufficient. Even for crypto-savvy interrogators, it may be nice: you're using no special software or algorithms, so its perhaps easier to plausibly deny any other secrets. Dedicated deniable encryption systems are really only worthwhile when, upon capture, you're going to try to game your interrogators, and feed them disinformation, and keep them guessing.