Know where you’re staying. Is there a room safe? If not, I would minimize the valuables. If there is no safe, I have a tendency to do 1 of 2 things. Lock my valuables in my suitcase and pray – or carry a Pacsafe. In my experience no one is going to risk their valuable job slashing open your luggage. But, when I’m traveling with my laptop and SLR and there is room in my bag, I will throw in the Pacsafe. This mesh thing wraps around your bag and affixes to a stationary object in the room. Anyone with a small hand can get into the mesh, so it’s a good idea to padlock any compartments containing small valuables. My fear isn’t the hotel staff, but more that other guests in certain types of places can get into the room.
You can also leave valuables with the front desk when there is no safe in your room. If they don’t have an individual safety deposit box you can lock yourself, put everything in a manila envelope, seal it with tape and write your name across the tape making sure to extend writing over the envelope. You should be able to tell if anyone opened the envelope.
If you don’t want to carry around a heavy Pacsafe and only need to secure your laptop, consider a Kensington lock. It locks into a slot on your laptop and a cable wraps around a stationary object in the room, like the Pacsafe.
Don’t carry things around that advertise your wealth. The first accessory I bought for my digital SLR was a non-descript strap that doesn’t have CANON DIGITAL EOS in 64 pt type! Yes, the camera is visible, but why have a billboard announcing it’s a new digital camera when the thief could possibly think it’s an older film camera? In the same vein, I wouldn’t carry a laptop bag with a huge Dell or IBM logo – in fact, I’d be more likely to carry it in a bag that doesn’t look like it would have a laptop inside.