I was mulling over trying to McGuiver a smoker out of my fire pit. The biggest problem is controlling the burn because it would be hard to control air ingress. I was thinking I could arrange charcoal brickets in a snake pattern so the burn is controlled by the diameter of the row. But it's kind of a silly idea given the irregularity of briquettes. Some people just put coal into a pit and burry the whole thing, and that works, so there is some hope I think.