You know, I didn't even think of a paint can, but that would be perfect if you have the chance to prepare one of these in advance. The lid would even give the coals some protection from rain or snow.

It occurs to me that a paint can (with or without pre-drilled holes) would make a good container for a small vehicular survival kit, or a part of a larger kit (with other gear packed in the can in either case, of course). I'm also thinking that 2-3 nails would have a lot of uses, and might make a good addition to my own PSK.