I just noticed that this thread is from 2005.
I was wondering why so many people were saying "just put it in your checked luggage".
Clearly that no longer works since (as I understand it) the security machine they run the luggage through now has a sensor that shows alcohol as a different color to flag it.
To those who are still interested in this thread....you can order a bottle of your favorite alcohol and have it waiting for you in your cabin through Bon Voyage.
You can not order it on line...you have to call them.
Carnival also does still allow one bottle of wine or champagne (750ml) per adult 21 or older . But you MUST carry the wine on...if you check it, it will be removed from your suitcase.