You can use your rice cooker for other grains besides rice. Barley is a whole grain that will contribute to the four servings of whole grains you should be getting daily.
Adapted from ehow.com
If you are using pearled barley, add the 1 cup of pearled barley, 2 cups of cold water and a pinch of salt to your rice cooker. If you are using brown barley, soak the cup of brown barley overnight in 2 1/2 cups of water and a pinch of salt. This step can be done inside of the rice cooker. For both types, cook through one rice cooking cycle. After the cycle is finished, let the barley rest for 15 minutes. Fluff the barley with a fork and serve or use in your favorite recipes.