Not quite an impulse buy, but mindful of my recent experience of being stung by a box jellyfish and being 'dumped' at the local government hospital where there wasn't even a doctor on duty, I decided to order a dog-tag with my vital information on it.
On one side is the usual personal information and on the other side (because I never know what country I will be in next), it says "I have hospital insurance" (which may or not be true!), in English, Thai, Lao and Burmese. However, in the case of where I'm unconscious and in a life-threatening situation (heart attack/car accident etc), hopefully this dog-tag will help me to be transported to a well-equipped private hospital where (with an awful lot of luck), they might believe the text on the tag and start treating me. I will worry about the costs if I am still alive afterwards...