This is the easiest way to go!
We just got home from our cruise to New England and we prepaid (always do). I just can't imange NOT doing this, it's so nice to know it's been taken care of in advance.
We too add a little note and a bit extra for service that is deserving of a little extra attention
2005 Carnival Spirit to Alaska
2007 Carnival Conquest to Western Caribbean
2008 Royal Caribbean Explorer of the Seas to New England/Canada
2010 Royal Caribbean Explorer of the Seas to Southern Caribbean