Wash rice in a colander to remove talc and any stones. Place in a rice cooker with 3 cups water and cook, Wait 15 minutes after rice has cooked before opening lid.
If you do not have a rice cooker. Put washed rice into a medium sized saucepan with a lid. Add water. Turn heat on medium high; when the rice starts to boil reduce heat to so that rice is just simmering. Allow rice to cook until all of the water has boiled off (about 15-20 minutes).
You may have to position the lid to allow the steam to escape. Taste the rice if it is still hard add a tablespoon more water and cook until the rice tastes done. If the rice is done, but is very wet, remove the lid and let the water evaporate. Remove from heat when done. The grains of rice should stick to each other, without being soggy.
While rice is cooking, cut spam into ten slices.
Combine soy sauce and sugar.
Heat 12 inch skillet; add soy mixture and saute spam slices over medium heat for about 3 minutes on each side or until most of the soy mixture has evaporated.
Remove from skillet and cool.
Cut each nori (seaweed laver) in half. The laver can be folded in half and torn along the seam.
Rub vegetable oil on inside of the musubi maker and the press. (or oil the inside of the spam can) This will make it easier to unmold.
Place one half sheet of laver on a flat surface and place the musubi maker (or spam can) on the laver.
Fill the spam musubi maker evenly with about 1 inch of hot rice. (If you do not have one, you can use the spam can. Cut off the other end of the can. tape the sharp edges. Cut a piece of a stiff plastic mat to just fit inside the spam can.)
Place one slice of cooked spam on top of the rice.
With the spam press (plastic), press down evenly on the spam slice.
Slide the musubi maker (spam can) up while pushing the press down to unmold the musubi.
Wrap one end of the laver over the spam and repeat with the other side. Gently move to a flat surface to cool.
Spam musubi can be frozen, thawed and reheated in a microwave.
You could also add kim chee, pickle, or a slice of egg omelet under the spam.
Cooked chicken breast (flattened), hot dog, sausage, or fish fillet can be substituted for the spam.
The spam can be "sandwiched" between two layers of rice instead of being on top. The rice tends to slide off, but will be held in place by the laver.