For the Lime Simple Syrup, mix sugar, water and salt in small saucepan. Bring to boil on medium heat. Remove from heat. Stir in extract. Set aside to cool. (This makes enough simple syrup for 8 Strawberry Lime Frozen Margaritas.)
Meanwhile, for the Lime Salt, mix salt and extract on small plate. Wet outside rim of 1 beverage glass with water. Dip glass into Lime Salt to coat. Set aside.
For 1 Strawberry Lime Frozen Margarita, place strawberries, tequila and 2 tablespoons Lime Simple Syrup in blender container; cover. Blend until smooth. Pour into prepared glass. Serve immediately. If desired, repeat to make additional margaritas, or, refrigerate remaining Lime Simple Syrup up to 2 weeks in an airtight container.