I always book the flights and cruise at the same time. May not be the smartest thing financially, but I always get my flights.
With fuel prices, the prices some of you were mentioning are awesome, not sure how long those will last.
The more time you are willing to spend searching for bargain air fares, the more likely you are going to find them.
Never had much luck booking bargain air fares with Southwest, no bargain seats available on the days I need to travel. Last time I booked them (Sacramento to Houston), I found out later, they were actually $100 per person more expensive than American West.