It turns out that smoke simulations both take far, far longer than rigid body simulations, but also take up a lot of disk space as well. So I might have accidentally filled my main C drive on which Windows lives and had all sort of complaints come screetching out of the operating systems.

In this sim I was just trying to figure out how the volumetic shaders worked, such that I could get a two stage explosion with thick, greasy smoke. You can see the secondary explosion in the second still. For an afternoons work, I was pretty happy!