I section about 15 oranges every other day at work, and always think it's a shame that I throw so much orange into the bin.
It finally struck me that I can make orange marmalade with all those orange skins and innards. The skins are especially valuable for making marmalade of any sort, because they contains loads of pectin.
So I consulted a great book on making preservatives, 'Well Preserved' where I found information for making marmalade, along with some variations: adding ginger, using brown sugar and a dash of molasses to make dark marmalade, etc...
The instructions say to take whole oranges, clean them thoroughly, slice them thinly, heat slowly for 20 minutes, add a volume of sugar equal to the volume of liquid, and then heat it for another 20 to 30 minutes until you hit the set point - 8 degrees Fahrenheit (4 degrees Celsius) above boiling point. Note that boiling point varies with altitude... since I'm close to sea level, the gel point is about 218F.
Because I had scraps instead of whole oranges, I put the scraps through the food processor's shredding blade and added a bit of orange juice to compensate for the missing sections. Heated the mixture, measured 2 cups of liquid and added 2 cups of sugar, then heated it to 218F and poured it into a very clean jar and put it outside to cool.