Stir together sugar and `1 cup water in a small saucepan. Cook over medium heat until sugar dissolves. Remove from heat, pour into large pitcher, cover and chill 20 minutes. Add lime juice, tequila, orange liqueur and cranberry juice to chilled sugar water. Chill until ready to serve. Rub glass rims with lime wedges, and dip rims in salt. Garnish with lime or orange wedge.
For frozen margaritas, process with crushed ice in a blender.