Alaska / RCL Vision of the Seas, May '98
Mediterranean / RCL Legend of the Seas, July '00
Caribbean / Celebrity Infinity, Nov. '00
Transatlantic / Pacific Princess Final Voyage, Oct. '01
Caribbean / RCL Adventure of the Seas, July '03
Caribbean / NCL Sky, June '04
Caribbean / Celebrity Horizon, Dec. '04
I've gone 10 days with just a carry-on. Of course, I used a laundromat during the course of my trip. Actually, I look up ahead of time the Post Offices within my destinations and actually mail my gifts (and dirty clothes) home. You would have to compare mail service with paying extra for heavy baggage, but sometimes it's worth it! One less bag to tote home. But alas, remember dirty clothes can smell, lol.
Throw a bottle of liquor in your carry-on, if it will fit. And then carefully 'stow' it on the airplane.
You can't take a large container of any liquid in your carry-on an a plane anymore. They might make you chug the whole bottle before you board.
More likely, someone in security will have a very pleasant evening after you are long gone...they will confiscate it.