Watched "Sunrise" this morning and they had a guy that has something to do with security and his recommendation for luggage security was padlock combination locks.
Like he said, if you buy the key ones, he said they are pretty easy to get into, whereas the combination ones are harder. He also mentioned cable ties but like he said you only need to cut these off and replace them. The wrapping thing was also mentioned. He said that was a good idea along with the combination padlocks, but not all airports have this service yet.
The guy also said that if you notice your luggage has been tampered with dont touch it and call security. He said once you touch the suitcase you are accepting it....