My husband convinced me it was time to get a locking gas cap for my vehicle. Normally when he ventures into the "paranoid" zone (and he is a frequent visitor), I humor him but don't usually change any of my habits. Now that it is costing about $60 to fill my gas tank, his suggestion has merit. It was easy to find one (apparently the gas cap size is one of the few things that is standard across most vehicles) and not too expensive (about $8). There is a little more hassle at the gas station since I have to take my keys with me, but I do have peace of mind. And so does my husband.