I recently found some wild tepin chile pepper plants in my back yard: http://en.wikipedia.org/wiki/Tepin
They are approximately as hot as a habanero. I was very lucky to find them because they are somewhat hard to grow from seed....they germinate best if the seeds are passed through bird droppings. I have found at least 3 plants in my back yard and 2 in my front. All have several tiny little red chiles on them (2 of them are loaded with red and green chiles so I will be well supplied for a while.) I have already picked some and made a chile garlic sauce (similar to sriracha sauce) out of them. It is very good and very spicy. I used 8 tiny tepin chiles (each about the size of a pencil eraser), 2 red bell peppers, 3 large cloves of garlic, and 3/4 cup white vinegar. Boiled everything together then pureed it. We tested it by mixing about 1/8tsp (serious, very tiny amount) with about 1/4 cup rice. It was delicious and not overpoweringly spicy but I also used a miniscule amount of sauce. The rest of the sauce is aging in the fridge, I am going to try making chili and adding a spoonful of the hot sauce to it later this week.
Any other suggestions for what I can use these incredibly hot chiles for? They should not be eaten straight since they are so hot. I am planning on using my "sriracha" sauce in lots of things like soup, chili, curry, stir fry, etc. I was thinking of trying homemade salsa but I have never attempted that before and wasn't sure how well the tepins would work for that, since they are so small, I think they would be very hard to cut. So if I were to make salsa, I would probably use my "sriracha" sauce in it since the tepins are already blended into that.