I've seen the $10 pashimas on the Grand Princess, the Norwegian Sun and the Carnival Conquest. I think it's a fairly standard item now, the new inch of gold, if you will.
One of my other favorites is to wear pareos as a skirt. Took me a while to figure out how to tie it so it hung right but now I love them. They pack down to nothing and can be tied around the neck for great bathing suit cover ups. I have a strapless suit and they look particularly good with that style. And they come in such great colors. Each one reminds me of the island where I got it. What a treat.