Yes, take the previous posters advice. If you're having a great time, sad that the cruise is so short and hoping you can do it again, do yourself a favor and book another cruise while you're on board (I think the future booking station is located on Deck 5 in the atrium).
This has the benefit of a reduced booking deposit (10% vs 20% if you book through normal channels) and can net you upwards of $200 in on board credit for your next cruise!
This was the MAJOR mistake the wife and I made on our last cruise. We were "worried" about money because we were going to WDW for our first time following the cruise and had NO idea what we would be spending while there for 7 days, so we figured we better "save" that deposit money. Now in hind sight, it's just a couple hundred bucks and we missed out on the $200 OBC.