Preheat oven to 325 degrees F.
Grease a 9 inch cake pan. Use a springform pan IF you have it for easier removal.
In a small bowl, combine graham cracker crumbs, sugar, and butter. Press into bottom of pan.
Bake for 10 minutes. Leave oven on, and remove to wire rack to cool.
In a large bowl, mix cream cheese, sugar, and flour until smooth and creamy. Add eggs one at a time.
Stir in eggnog, nutmeg, rum extract, and salt.
Pour filling evenly over crust.
Place ~1 inch of hot water in a large baking pan. Add springform pan into baking pan.
Bake at 325 degrees for ~45-50 minutes or until the center is set.
Remove from water bath. Cool on wire rack.
Refrigerate 4-6 hours.