Hi,
I am a former professional photographer who is now into digital photography.
My first suggestion would be to purchase an additional card. You should always have backup. Cards are coming down in price, especially if you get one over the internet and not at a store. Pricescan.com or Pricegrabber.com would be good places to research prices.
I'm not sure how much cheaper getting a CD burned would be. Retail price for that type of work is generally between $10-$20. On a cruise ship I would not be surprised is that fee is at least doubled. On a seven day cruise it could be possible that you would need 2-3 CD's burned.
Another option would be to bring a laptop with you. If you do not own one, perhaps you could borrow one for the week. You would need to load the software that came with the camera onto the laptop so that uploading the images would be easy and familiar. I will be bringing a laptop to my cruise for this very purpose.
Once you get back home, if you don't have a network setup, or the laptop does not have a built in burner, you could then transfer the pictures back to your camera's card, and then upload from the camera to your home PC. Time consuming but very doable.
There is a last option but it is not cheap. Personnel Storage Devices. These are units that are specifically designed for transfering images from a memory card and storing them. They usually come in sizes ranging from 10GB's to 40GB's. They can hold a years worth of images. Many of these devices also can function as an MP3 player. Archos makes a device called a Gmini which has gotten good reviews (
www.dpreview.com , go to the storage & media forum). This particular unit retails around $200, but may need and attachment depending on what kind of card your camera uses. That may add $25 to the price. If you were looking for an MP3 player anyway, this may be a good option.
Hope this helps.
