Peel the oranges and quarter the fruits. Using a food processor, pulse the peel and the fruit until quite fine. Peel the rhubarb (if quite large). Chop the rhubarb into small pieces. Mix the rhubarb and oranges with the sugar, and allow to sit overnight.
In a heavy pot, bring the mixture to a boil. Add the pectin and cook for one minute (or according to the pectin directions.) Pour into jars and seal. Enjoy!
Nutritional analysis per tablespoon: 55 calories, .11 grams protein, 14 grams carbohydrates, less than 1 gram fat, 8 mg. sodium, less than 1 gram fiber.