Process half of first 4 ingredients in blender til smooth. Pour mixture into a 4 1uart plastic container. Repeat procedure with remaining half of ingredients. Freeze til firm.
Rub rims of stemmed glasses with lime wedges. Put salt in saucer; spin rim of each glass in salt.
Remove container from freezer 30 minutes before serving; add club soda, stirring til slushy. Pour into glasses. Makes about 12 cups.
Note: For the alcoholic version, stir 1 cup tequila into mixture before freezing.