Burke’s Backyard resident scientist, Graeme Quirk, demonstrated how to speed up the cooking time of whole potatoes in a normal oven. You simply push some big stainless steel nails into the centre of each potato. Nails are excellent thermal conductors and carry the heat right to the inside of the potato. The result is that all of the potato is rapidly cooked at once, rather than cooking from the outside in, which takes longer. Metals other than stainless steel will also conduct heat, but may contaminate food.
Warning: do not try this method in a microwave oven, and don’t forget to remove the nails before serving!