Freeze the bowl of an ice cream maker overnight.

Place the cranberries, sugar, and orange juice in a medium pot, and cook over medium-low heat for 5 to 10 minutes, or until most of the berries have burst.  

Transfer the mixture to a blender or food processor, and process until smooth. 

Chill overnight.

Process the cranberry mixture in the prepared ice cream maker for about 20 to 25 minutes, or until it's the consistency of soft-serve. 

Transfer the sorbet to a loaf pan, and freeze overnight, or until hard.