These rich, citrusy desserts are the perfect end to a summer meal. You can substitute an equal amount of lime juice for the tequila and triple sec, if you prefer.
In the bowl of an electric mixer, beat cream cheese until smooth. Add sour cream, confectioners' sugar, lime zest, lime juice, tequila, and triple sec; beat until combined. (You can substitute lime juice for the tequila and triple sec.) In another bowl, whip heavy cream until stiff peaks form; fold into cream-cheese mixture. Cover with plastic wrap; freeze until firm, about 30 minutes.
Pulse granulated sugar and graham crackers in a food processor until finely chopped; stir in melted butter. To serve, place lime juice on one plate and salt on another. Dip rims of glasses in juice, then salt. Remove mixture from freezer, and scoop into glasses; sprinkle with topping. Let soften slightly before serving.