our cabin steward loved it too, as it helped her learn our names. I thought it was great...remember you are on a ship with a ton of others that you will never see again, but are all there for fun and excitement. I can't think of a reason you wouldn't want someone to know your name on the boat? I think it's a way to get to know people.
You can buy rolls of magnets at any craft store and attach them to the back of a peice of paper, or I heard there is some sort of paper you can magnatize, but that was way beyond me!
The best suggestion I have ever seen was to make a sign and laminate it, then hang a permanent pen and put a sticky note suggesting other passengers make notes, say HI, or whatever...great scrapbook item! have fun!