Thanks very much for all the tips, now I'm thoroughly confused! Wouldn't like to go along the cable tie route with nail clippers in outside pocket, in case the nail clippers got nicked and I was unable to cut the cable tie. I've bought a TSA padlock, but am now worried about using it, in case a US customs person doesn't know how to unlock it, and rips my case apart! Maybe just leaving it unlocked is the best idea, but have to admit I'm a bit nervous about doing that.