Combine crumbs, sugar, nutmeg and margarine; press onto bottom of 9-inch springform pan.
Soften gelatin in water; stir over low heat until dissolved. Combine cream cheese and sugar, at medium speed on electric mixer until well blended. Gradually add gelatin and eggnog, mixing until blended. Chill until slightly thickened; fold in whipped cream. Pour over crust; chill until firm.
Ingrease sugar to 1/3 c. Substitute milk for eggnog. Add 1 t vanilla and 3/4 t rum extract. Continue as directed.