In a large saucepan of boiling water blanch the peaches and the nectarines for 30 seconds, drain them, and let them cool. Peel, pit, and slice the fruit. In a large saucepan combine the sugar with 1/2 cup water, bring the mixture to a boil, stirring, and simmer it for 4 minutes. Add the fruit and the lemon juice and simmer the mixture for 15 to 20 minutes, or until the fruit is soft. Stir in the Southern Comfort, a pinch of salt, and the cinnamon. In a blender or food processor blend the mixture until it is smooth, transfer the puree to a bowl, and stir in the almonds. Serve the sauce warm.