I bring a lot of stuff when I travel. A lot of hotels have in-room safes, others don't... specially when you're backpacking around a city or country. One of the most useful travel gadgets I own is a Pacsafe 85L safety mesh bag.
Essentially a steel cage that you can wrap around any existing bag or backpack. The long security cable can be fastened around a post or rail to prevent snatching.
Simply place it over your bag, tighten the securing cable lock, and padlock (it comes with a Pacsafe padlock & key, but I upgraded mine to a Pacsafe TSA combination lock instead)
It gets you funny looks at airport security, but eventually becomes a topic of conversation with security personnel.
It's not 100% fool-proof, anyone with wire or bolt cutters will be able to get to your bag, but it will deter a lot of pick-pockets and casual thieves, specially when traveling by train in other countries.
Highly recommended for backpackers and adventurers that want to keep their stuff safe while on the move.
**Hallo, ich lerne Deutsch und ich kann ein paar Fragen zu beantworten.
Je parle un peu français aussi. Je peux répondre à des questions sur mes messages.**