With a sharp knife, cut the kernels from the corn cob, and use the back of the knife to rub the milky juice from the cob (you'll see, there's a little bit of the kernels that gets left behind, and you can get some sweet yummy juice by scraping them). Melt the butter in a saucepan over medium heat and throw all the corn in. Heat the corn through, maybe a couple of minutes. Just before serving, sprinkle with the chili powder and pour the lime juice over the corn. Just stir it up and enjoy! Best corn EVER.