Let's see now.. a mini flashflight (in case its dark<G>), a travel steamer ( since ships frown on irons in the cabins), a multi plugged extension cord with surge protector (because most cabins have only one, or maybe two electrical outlets)...
and after our last cruise an extra laptop and digital camera (because both quit working on me.. and that's not a good thing when you're supposed to be sending back stories and pictures from the ship )<G>
I'm with Mermaid's backpack -- it's essential for us! Great for taking water bottles and cameras on shore excursions, and perfect for throwing in liquor we buy and T-shirts. *Every* cruise we say how we could never do without it.
Hmmm ... my othet two small items are a can of air freshener in case the room smells closed-up and a small highlighter pen to mark the daily newsletter of what I would like to do the next day.
Handy Travel Sizes of everything I can't live without. When a headache, sore throat, upset stomach, cut, ache or pain exists, I don't want to have to wait for a store to open or bother with an infirmary. I pack my personal first aid kit including cough drops, Pepsid, feminine supplies, aloe lotion, etc. Yes, I was a Girl Scout!
Have only been on one cruise before and am awaiting my second in August. On my first there were 3 of us and I got the bunk. I found the room to be very dark at night and on cloudy days and the first couple of trips to the bathroom, down the ladder, was exciting. So, this time I'm taking a nightlight although I won't be in a bunk.
Bring a half dozen clothespins to weigh down the shower curtain. We found them to be very helpful last month on Royal Carribean. My mother was jealous she hadn't packed any for her cabin. Just put them along the bottom and that darn curtain won't touch your body or become stuck to you. Yuch!
One thing I was really glad I brought with me on my last cruise was a hanging shoe rack with pockets. It folds flat in the suitcase and was great hanging in the closet with my shoes. My hubby said I brought too many shoes with me, but they were all in one place and out of the way. You could even bring an extra one to hang over the bathroom door with shaving gear, etc. in it. I got mine at the dollar store and just threw it away after the cruise. Shoes cause clutter. I loved mine hanging nicely.