Many of the principles that Kevin outlines for laptops can be extended to any valuable item that is carried while travelling.
Typically, when I travel, I divide my luggage into three groups; those things which I must not lose under any circumstances; items which would be a major pain to lose, but not necessarily a showstopper; and those items which, if lost, would be an inconvenience, but otherwise I’m not particularly concerned about.
In the first group go important items like passports, drivers’ licences, plane and train tickets, credit and ATM cards, travellers’ cheques and money. I carry all of these in a money belt, worn under my clothing. Now, this may seem inconvenient, and I’ll admit, the first time I tried it, it did feel strange, but I quickly became accustomed to it, and now when I travel, I don’t notice that it’s there at all. The number of items that I’ve listed makes it sound like I’d be carrying a brick around my waist, but in practice, it’s not large or heavy at all.
The important thing to note here, however, is that the money belt must be worn under your clothes to be effective; that means underneath your trousers and shirt. If you wear it on the outside of them, you’re just asking for it to be pick-pocketed. Pick-pockets rely on not being detected while stealing your valuables – it would be a particularly brazen pick-pocket that attempts to get a money-belt from underneath clothing, and you’d be bound to notice them doing it.
The second group of items tend to be expensive equipment, like cameras, mobile phones and occasionally laptops. I try to keep these to a minimum; there’s nothing worse than lugging heavy equipment around with you. The one time I’ve travelled with a laptop was on the way home from an IT conference, and it became an awful pain. I carry all these items in a small backpack, which never leaves my side unless it can be stored safely away in a locker (for example, at railway stations). On the rare occasions that I do that, I padlock the small backpack to my larger backpack, as the two bags together would be somewhat cumbersome to a thief (of course, they could just slash the bags open and steal the contents).
The final group of items are mostly clothes, towels and books; generally things that a thief doesn’t want, and while it would be inconvenient to lose them, it’s generally easy to replace them while travelling. These go in my main backpage, and while I make all endeavours to prevent it from being stolen (eg, padlocking or chaining it to furniture), there are always going to be times when that’s not possible. Plenty of youth hostels and backpackers’ hotels, for example, do not provide lockable lockers, and luggage either has to be left in an cupboard, at best, or on top of your bed at worst. Obviously, you’d be mad to leave anything of any value in your bag in such a situation.
Finally, if you’re still under any illusion as to how pickpockets work, then it’s well worth checking out this video: