Magnetic buttons
If velcro doesn't do it for you, someone somewhere in Hokkaido, Japan--specifically World Work Company which doesn't seem to have a Web site (surprise, surprise)--has come up with magnetic buttons. Developed more for the elderly and disabled, one assumes these fasten on really well and won't pop open as easily as they snap close. There's a reason magnetic buttons haven't become a standard fastening mechanism for clothing, besides being customs checkpoint-unfriendly. Still, the Japanese have added their own meticulous touch with special coating to prevent rust. Yaka!
