it's illegal for shops to sell it in the US, kinda like redbull is illegal to be sold in canada, but you can bring a certain amount back with you from other countries.  they didn't hassle me at all when i brought it back from london, and i wasn't even legal drinking age at the time.  it's decent stuff, tastes alot like licorice (think hectic jagermiester)  and supposedly the wormwood content makes you trip face.  it really just gets you sloppy drunk unless you blow a line of K or something, then you might trip like you would on mushies.  i dunno, mixing drugs is sketch, so do what you want.  you can order online www.seborabsinthe.com, but i suggest finding someone to brink it back, because they charge an arm and a leg to have it sent to the states.  plus they will only ship the 55% alcohol by volume, where as there are kinds that exist up to 85% if you buy it in a legal country.
on another note, i would just suggest getting mexcal from mexico.  it's a for of agave tequila that basically is the mexican version of absinthe.  but it fucks you up more, makes you trip more,a nd is much cheaper.  and it tastes like tequila instead of licorice.  oh, and you get a nice case of the shits the next day unledd you can really handle your tequila
_____________________________
 this is the life God chose for me...