Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
2         ounces        tequila 
1         ounce         Cointreau 
1/2       ounce         lime juice

Preparation:

Shake with cracked ice. Strain into prepared cocktail glass (moisten rim of chilled cocktail glass with a lime and dip into Kosher salt).

Skip's Variation: Use Triple Sec instead of Cointreau, and lemon juice instead of lime.