I found this on the Esquire Magazine website.
In fact, in the August '08 issue, the magazine spotlights absinthe as modern variants of it are becoming legal in the States.
Absinthe Frappé
1 ounce absinthe
˝ tablespoon superfine sugar
1 ounce water
Instructions
Pour the absinthe, sugar (the quantity will need to be adjusted according to the brand of absinthe, as they vary greatly in sweetness), and the water into a blender.
Blend for a moment to dissolve the sugar and then, with the blender running, add 3 or 4 ice cubes through the hole in the top, pausing between cubes to let them get crushed. Blend until smooth.