We use these Lucky Line Flex-O-Locks on every zipper on our bags. I caught one pick-pocket on the metro in Paris trying to get into my back pack while I was distracted with my children. I caught him, shook my finger at him and he shrugged and walked away. He never did figure out how to open them!
I prefer locking S-biners. I use them on my purse zipper and also on my pack.
The screw type cable keychain loops at Wal-Mart are similar and only cost about $1 each at the counter where keys are cut.
Small, combination luggage locks work well.
Thanks for the tip. I may have to try them. Like Cindy, I have used the locking s-biners for years.
There are also plain silver twist-to-open ones on Amazon. I use locking carabiners from Eddie Bauer, they come in various sizes.
I have a Pacsafe backpack that is excellent protection against pickpockets and I wear pants by Clothing Arts that are pick pocket proof. I work to hard to afford to take trips to Europe to have to deal with lost passports or my credit cards or cash.