You can get Absinthe in the US but you have to order it from Europe and get it shipped here at ridiculous prices and wait for a long time. This is widely regarded as a "pain in the ass."
Lucid Absinthe is set to begin shipping next month to locations throughout the US. They were able to pass regulatory muster by getting rid of all the thujone (the banned ingredient) in their product. However, they were able to use certain European herbs in order to make up for the taste difference.
So, you can finally bring Absinthe to the party and be the toast of the ball. One of the unintended side-effects of Absinthe coming to the US though, will be a significant reduction in posts from Liquor Snob, they can't seem to keep their hands off the stuff.
Keep an eye on their site for a liquor store selling it near you.
Lucid Absinthe - US$59.95
Edit: Erik added some comments that fleshed out the Thujone issue as well as some Absinthe background.
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