A Toronto family has paid to have the remains of their late grandmother turned into a diamond. Came out to be a quarter-carat stone. It seems like a perfectly acceptable alternative to burial, as that process takes up much needed land in some countries, and is rather expensive. And from what I understand, it's very difficult to procure a burial service in some parts of Europe because of the lack of space.
Link to story.
I guess the real question in the whole diamond idea is whether the surviving members should be picky about the stones quality (cut, color, clarity). Gives a whole new meaning to "wearing grandma's jewelery" as well.