4 lime slices
coarse salt (optional)
2 cups ice cubes
1 (6 oz.) can (3/4 cup) frozen limeade, thawed
3/4 cup tequila
1/4 cup triple sec or other orange liqueur

Rub lime slice around rim of 4 glasses. Reserve lime slice. Dip rims of glasses into salt if desired. Combine ice and next 3 ingredients in blender and blend until smooth. Pour into glasses and garnish with lime slices.