Mix together sugar and water in a small saucepan. Cook until the sugar is dissolved. Remove from heat, pour into a large pitcher, and cool in the refrigerator about 20 minutes.
Next add the lime, tequila, orange liqueur, and cranberry juice to the pitcher of simple syrup. Mix well, and chill until ready to serve.
Rub glass rims with lime wedges, and dip in salt.
Serve over crushed ice. Or blend with ice for a frozen margarita.